Metal part inspection device and inspection method

Abstract

The present invention relates to an apparatus for inspecting the surface of a metal part, the apparatus comprising a plurality of geometric profile sensors (10) mounted on a frame (1) at intervals, a plurality of eddy current sensors (20) mounted on the frame (1) at intervals and directed toward the surface of the metal part to be inspected; relative longitudinal movement and optional relative rotational movement between the frame (1) and the metal part during operation of the apparatus; an electromagnetic signal electronic multiplexing circuit for receiving and processing signals acquired by the geometric profile sensors (10) and the eddy current sensors (20) in real time; and an interpretation / evaluation unit for receiving the signals processed by the electronic multiplexing circuit and identifying defects on the metal part surface. The present invention relates to a method for inspecting the geometric shape of at least one segment of the surface of a metal part, the method being implemented in the apparatus and for identifying geometric defects using data acquired by the geometric profile sensors (10) and for identifying surface defects using data acquired by the eddy current sensors (20).

Description

[Technical field]

[0001] The present invention relates to an apparatus and method for inspecting the inner or outer surfaces of metal parts along regular segments which may be cylindrical, solid or hollow, such as tubes, pipes, ducts, mandrels, shafts, various geometrical contours (or profiles), plates, and tools used in the manufacture of metal parts in general, and tubular parts in particular. [Background technology]

[0002] State of the art The evaluation of the external or internal surfaces of metal parts such as tubes, pipes, ducts, mandrels, shafts, contours (or profiles), and the tools used to manufacture these parts is a critical step in the manufacturing process of these products and in monitoring the integrity and geometric fit of these tools. Monitoring the condition of these parts is essential to ensure their proper functioning. Therefore, different types of non-destructive testing are used to evaluate these parts.

[0003] These evaluations are currently performed with different devices for different situations. Document AU2015200693, which constitutes the state of the art, discloses methods and devices for acquiring and processing data from a number of different types of sensors for non-destructive testing of metallic structures. These methods and devices are used to acquire data from the finished product and not during its manufacturing process. Signals from an electromagnetic acoustic transducer (EMAT), eddy current (EC) signals, magnetic flux leakage (MFL) signals, and deflection signals are acquired from each of a number of localized regions of the metallic structure and processed to characterize one or more properties of the metallic structure based on at least two of the acquired signals from the EMAT, EC, MFL, and deflection signals from a common localized region in which at least a portion of the properties are located. An integrated multi-sensor non-destructive testing device may be used to provide EC, EMAT, MFL, and deflection signals for each of a number of localized regions of the metallic structure. These integrated multi-sensor devices may be configured to provide an in-line inspection tool, such as a smart pig used for pipeline integrity inspection.

[0004] Generally, pig-type probes are used, passing them through metallic parts with a specific type of sensor. However, their use is related to the detection of more serious defects in cylindrical structures. Furthermore, the above mentioned document addresses the combination of different types of sensors to obtain a result. However, the tools as described in said document are very costly and highly complex, which means that this solution is not viable for detecting small defects in tubular profiles. The pigs disclosed in this prior art only function to evaluate the surfaces of cylindrical parts and are not suitable for evaluating the surfaces of plates and hollow parts with different shapes and cross sections.

[0005] US4818935 discloses a method and apparatus for non-destructive testing of defects in metallic materials, comprising an excitation coil arranged around the longitudinal cylindrical or columnar axis of the material to be tested. A relatively low frequency multi-frequency alternating current is used to cause the excitation coil to generate a rotating magnetic field around the longitudinal axis of the material to be tested. This multi-frequency current is superimposed with a high frequency alternating current having an inspection frequency selected based on the sensitivity required to detect surface defects in the material to be tested. By applying this composite multi-frequency current to the excitation coil, the electromagnetic effect induced on the surface of the material to be tested by the high frequency alternating current is rotated in the circumferential direction of the material to be tested together with the rotating magnetic field. A group of detection elements arranged near the surface of the material to be tested detects the change in the electromagnetic effect depending on the presence or absence of surface defects in the material to be tested.

[0006] US6404189 discloses a method and apparatus for implementing magnetostrictive sensor technology for non-destructive evaluation of pipeline structures. The apparatus comprises a magnetostrictive sensor equipment unit, a data storage unit, and a number of magnetostrictive sensor probes arranged on an in-line inspection vehicle. The equipment unit includes electronics for transmitting excitation pulses to the transmitting magnetostrictive sensor probe and electronics for amplifying and conditioning the signal detected by the magnetostrictive sensor probe receiver. The magnetostrictive sensor probe includes both a plate-shaped magnetostrictive sensor and a permanent magnet that provides the DC polarizing magnetic field required for the operation of the magnetostrictive sensor; the transmitting and receiving probes are attached to the in-line inspection vehicle via mechanical arms on opposite sides of the in-line inspection vehicle. The mechanical arms are spring-loaded and include rollers to keep the probe at a substantially constant distance from the inner diameter of the pipe wall. The method involves generating horizontal shear wave pulses at a frequency of less than 200 kHz. The transmitting magnetostrictive sensor probe generates waves that propagate in both directions around the pipe wall from a point adjacent to the transmitting probe. Both waves are then received by the receiving probe, which is 180 degrees away from the transmitting probe. Any imperfections in the pipe wall within the surveyed perimeter will be reflected in the received signal.

[0007] The US6924640 document discloses an inspection device for detecting defects in ferromagnetic pipes used in drilling oil and gas wells. The inspection device operates inside the pipe by first saturating the pipe wall with magnetic flux. Defects along the pipe wall cause leakage of magnetic flux, which is measured by Hall effect sensors arranged in the inspection device. The magnitude of the leakage flux is related to the amount of material loss. Eddy currents induced in the wall are also measured and combined with the measurements of the Hall effect sensors to determine the location and geometry of the defect.

[0008] Although various non-destructive pipe inspection devices are already known, there is currently no device in the state of the art that is able to combine two different types of sensors, one an eddy current sensor and the other a magnetometric sensor, in order to capture, process and combine real-time data and provide an analysis and reconstruction of different types of defects detected in metal parts of different shapes (or forms or geometries), in particular longitudinal defects such as cracks, microcracks, bends, bumps, scratches, and geometric defects on the pipe surface such as ovalization, dents, crushing, warping, scaling, buckling, etc. Summary of the Invention [Problem to be solved by the invention]

[0009] Object of the invention A first objective of the present invention is to provide an apparatus and method for performing real-time, in-line inspection of tubular metal parts, their manufacturing tooling, and generally metal parts having various shapes and cross sections, by combining different types of sensors that provide a broader range of results, identifying various types of defects, including longitudinal (or vertical) defects such as cracks, microcracks, scratches, and defects in the geometric shape (or contour or profile) of the metal part surface such as ovalization, dents, crushing, warping, scaling, buckling, and the like.

[0010] It is another object of the present invention to provide an apparatus and method for acquiring, processing, and analyzing detailed data about various types of defects found in inspected metal parts, and automatically characterizing and classifying them into various types based on this data. [Means for solving the problem]

[0011] BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS The object of the present invention is to provide a metal part surface inspection device, Frame; Multiple geometric profile sensors mounted on the frame and spaced well apart; a plurality of eddy current sensors mounted on a frame and facing the surface of the metal part being inspected; whereby, while the device is operating, there is a relative displacement between the frame and the metal part to be inspected; an electromagnetic signal electronic multiplexing circuit that receives the signals acquired by the multiple geometric profile sensors and the eddy current sensors and processes them in real time; An interpretation / evaluation unit that receives the processed signals from the electronic multiplexing circuitry and identifies defects on the metal part surface Includes.

[0012] The frame can include at least one geometric profile sensor support on which the geometric profile sensor is mounted, the geometric profile sensor support having a cross-section that matches a cross-section of the metal part segment under inspection.

[0013] At least some of the geometric profile sensors are preferably articulated to the frame and may include a rod having a first side coupled to either the frame or the geometric profile sensor support and a second side coupled to a contact tip, the frame-mounted rod having a magnet attached to its first side, and the contact tip of each geometric profile sensor moves over the metal part surface under inspection during relative displacement between the metal part and the frame.

[0014] A bearing can be rotatably coupled to the contact tip of the geometric profile sensor, such that the bearing rolls along the entire length of the metal part surface segment being inspected.

[0015] At least some of the geometric profile sensors may be one of laser point sensors or laser line sensors, and the laser sensors are mounted to one of the frame or geometric profile sensor supports.

[0016] The geometric profile sensor may further include an encoder coupled to the bearing, where the encoder determines a longitudinal (or vertical) position of a measurement taken on the inspected part based on movement of the bearing over the inspected part surface and transmits corresponding longitudinal (or vertical) position data of the measurement to the electromagnetic signal electronic multiplexing circuitry.

[0017] Alternatively, at least one spring is coupled to a first side of each rod and to one of the frame and the geometric profile sensor.

[0018] Each eddy current sensor may include a shoe and at least two coils coupled to the shoe, where each shoe is attached to one of the frame or the geometry sensor support and remains in proximity to the metal part surface during relative displacement between the metal part and the frame. Each eddy current sensor measures interference between a magnetic field generated by the coils and a magnetic field generated by induced eddy currents in the metal part segment under inspection.

[0019] The frame may include at least one eddy-current sensor support on which the eddy-current sensor is mounted.

[0020] The positioning and number of eddy current and geometric profile sensors used are preferably based on predetermined resolution and redundancy criteria, with each of the eddy current and geometric profile sensors independently mounted on an articulated arm.

[0021] The eddy current sensors and surface geometric profile sensors are preferably uniformly distributed in at least two regions in at least two defined rows, with an offset between adjacent sensors in two consecutive rows, the offset being less than the width of a single eddy current sensor.

[0022] The multiplexed electromagnetic signal electronics converts the signals acquired by the multiple geometric profile and eddy current sensors into digital signals and transmits them to an interpretation / evaluation unit, which analyzes and standardizes the signals, reconstructs defects, analyzes defect parameters, and classifies identified defects.

[0023] The geometric profile sensor identifies defects in the geometric profile of the surface of the metal part being inspected, while the eddy current sensor identifies defects such as cracks, microcracks, scratches, and small dimensional mass loss (or pitting or pitting).

[0024] The eddy current sensor operates in one of the following configurations: absolute configuration (or absolute geometry), differential configuration, pickup configuration, and pulsed eddy current (PEC) configuration. The magnetic sensor used in the surface geometric profile sensor is one of the following: Hall sensor, Giant Magnetoresistance (GMR) sensor, and Superconducting Quantum Interference Device (SQUID) sensor.

[0025] The inspection apparatus may include a plurality of rods mounted on a frame, each rod having a geometric profile sensor and an eddy current sensor, where the eddy current sensor is disposed at a contact tip of the geometric profile sensor.

[0026] In the inspection apparatus, the frame and the sensor support may be rotatable around the metal part to be inspected. A motor may be attached to the frame to drive the rotational movement. If the inspection apparatus is configured to inspect the inner surface of the part, the inspection apparatus may include a number of wheels attached to the outer surface of the apparatus for sliding on the inner surface of the part to be inspected. The rotational movement of the frame driven by the motor causes longitudinal movement of the inspection apparatus over the inner surface of the part. Alternatively, the frame may be connected to a traction mechanism that moves the frame inside the metal part to be inspected.

[0027] The object of the invention is also a method for inspecting at least one segment of a surface of a metal part, the segment having a defined geometric shape, which is carried out by means of the above device, comprising the steps of: - carrying out a relative displacement between the device frame and the metal part to be inspected, and during said displacement; - Identifying geometric defects on the surface of the metal part under inspection based on data obtained from a geometric profile sensor; -Identifying surface defects based on data obtained from eddy current sensors This is achieved by a method comprising:

[0028] According to one embodiment of the present invention, during the relative displacement between the device frame and the metal part to be inspected, a.1) A geometric profile sensor obtains measurements related to the geometric shape of the surface of the metal part under inspection. a.2) Eddy currents are induced in the metal part segment under inspection. a.3) The eddy current sensor measures the interference between the magnetic field generated by the coil and the magnetic field generated by induced eddy currents in the segment being inspected. a.4) The geometric profile sensor and the eddy current sensor transmit their analog measurement results to an electromagnetic signal electronic multiplexing circuit. b) The electromagnetic signal electronic multiplexing circuit converts the captured analog data from step a.4) into digital data and transmits it to an interpretation / evaluation unit. c) An interpretation / evaluation unit identifies defects on the metal part surface based on the signals acquired from the geometric profile sensor and the eddy current sensor.

[0029] Preferably, in step a.1), the contact tips of at least some of the geometric profile sensors are moved over the surface of the metal part under inspection and the magnetic sensors detect the magnetic flux generated by the magnets during the respective movements of their joints with the frame of the geometric profile sensors.

[0030] In step a.1), a laser sensor may preferably determine the geometrical variations of the surface of the metal part under inspection and transmit the acquired measurements directly to an interpretation / evaluation unit.

[0031] Preferably, the interpretation / evaluation unit analyzes and standardizes the signals received from the electromagnetic signal electronic multiplexing circuit, reconstructs the defects, analyzes the defect parameters, and classifies the identified defects. Surface defects include cracks, microcracks, scratches, bends, and bumps, and geometric defects include ovalization, eccentricity, dents, collapse, warping, material buildup, and buckling.

[0032] The step of implementing a relative displacement between the apparatus frame and the metal part to be inspected may include one of the following: - Moving metal parts inside the equipment frame in order to inspect their outer surfaces. - Moving the device frame outside the metal part to inspect the outer surface of the metal part. - Moving metal parts outside the equipment frame in order to inspect their internal surfaces. - Moving the device frame inside the metal parts to inspect their inner surfaces.

[0033] For a better understanding, the features and advantages of the present invention are shown and described in conjunction with representative drawings illustrating several preferred forms of the invention. [Brief description of the drawings]

[0034] [Figure 1] FIG. 1 shows a perspective view of an inspection device according to an embodiment of the present invention. [Diagram 2] FIG. 2 shows a side view of the inspection device shown in FIG. [Diagram 3] FIG. 3 shows a front view of the inspection device shown in FIG. [Figure 4] FIG. 4 shows a rear view of the inspection device shown in FIG. [Diagram 5] FIG. 5 shows a perspective view of an eddy current sensor used in the inspection device of FIGS. [Figure 6] FIG. 6 shows a side view of the eddy current sensor of FIG. [Figure 7] FIG. 7 shows a side view of a geometric profile defect sensor used in the inspection apparatus of FIGS. [Figure 8] FIG. 8 is an example of a metal part sample to be inspected. [Figure 9] FIG. 9 illustrates a signal indicative of a defect in the surface of a metal part under inspection, as identified with the apparatus of the present invention. [Figure 10] FIG. 10 illustrates surface defects identified at various processing steps by the apparatus of the present invention. [Figure 11] FIG. 11 is a schematic front view of an apparatus of the present invention performing inspection of the outer surface of a part of circular cross section. [Figure 12] FIG. 12 is a schematic front view of the apparatus of the present invention performing inspection of the inside surface of a part of circular cross section. [Figure 13] FIG. 13 is a schematic front view of an apparatus according to the invention performing inspection of the inside surface of a metal part in the form of a plate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] Detailed Description of the Invention Figure 1 shows a preferred embodiment of the metal part inspection device to which the present invention is addressed. The metal parts may be cylindrical, solid or hollow, for example tubes, pipes, mandrels, shafts, profiles of various geometric shapes, sheets, tools for the manufacture of metal parts in general and tubular parts in particular.

[0036] The apparatus comprises a frame 1, to which a number of geometric profile sensors 10 are articulated. The geometric profile sensors 10 are regularly distributed and spaced apart from one another so as to cover the entire metal part surface to be inspected in radial and axial directions. The geometric profile sensors 10 identify geometric shape defects such as, inter alia, ovalization, eccentricity, dents, crushing, warping, scaling and buckling. During operation of the apparatus, there is a relative displacement between the frame 1 and the metal part to be inspected.

[0037] In the embodiment of the invention shown in Figures 1 and 4, a frame 1 includes a geometric profile sensor support 13 attached thereto. The geometric profile sensor may be attached directly to the frame 1 or to a support 13. The geometric profile sensor support 13 has a cross-sectional shape that matches the cross-sectional shape of the metal part segment being inspected. For example, if the metal part under inspection has a circular internal or external cross-section, the geometric profile sensor support 13 may be disk shaped.

[0038] FIG. 11 illustrates an embodiment of the invention in which a metal part has a tubular shape with a circular cross-sectional profile and the apparatus of the invention inspects the outer surface of the part.

[0039] On the left side of Figure 11, the geometric profile sensors 10 are illustrated spaced circumferentially around the entire circumference of a disk-shaped geometric profile sensor support 13 mounted on a frame. In this embodiment of the invention, the disk-shaped support 13 may be moved relative to the frame to which it is mounted so that it is traversed by the metal part to be inspected. In the apparatus of the invention, one or more geometric profile sensor supports 13 may be coupled with the geometric profile sensor 10 and arranged in series on the frame to achieve higher resolution and more reliable measurements.

[0040] The apparatus of the present invention further includes a plurality of eddy current sensors 20 mounted on the frame, also spaced apart from one another. In the embodiment of the present invention shown in Figures 1 and 3, the frame includes at least one eddy current sensor support 23 to which the eddy current sensors 20 can be mounted.

[0041] Thus, when there is a relative displacement between the frame and the inspected metal part, the eddy current sensor 20 also covers the entire inspected metal part surface in the axial and radial directions. The eddy current sensor 20 obtains data generally relevant to identifying defects such as cracks, microcracks, bends, scratches, bumps, and pitting.

[0042] On the right side of Fig. 11, eddy current sensors 20 are shown spaced circumferentially around a disk-shaped eddy current sensor support 23 mounted on a frame. The disk-shaped support 23 is traversed by the metal part to be inspected as the metal part is moved relative to the mounted frame. In the device of the invention, one or more geometric profile sensor supports 23 may be arranged in series on the frame in combination with the eddy current sensors 20 to achieve higher resolution and reliability of the measurement results.

[0043] 1-4, the apparatus includes one geometric profile sensor support 13 and three eddy current sensor supports 23 arranged in series. However, the apparatus may include a different number of geometric profile sensor supports 13 and eddy current sensor supports 23 depending on the desired inspection resolution and the redundancy or reliability of the measurement results desired through the inspection. The geometric profile sensor supports 13 and eddy current sensor supports 23 are preferably aligned such that the metal part to be inspected can be subjected to measurement by the geometric profile sensor 10 and the eddy current sensor 20 sequentially while there is a relative displacement between the frame 1 of the apparatus and the metal part for carrying out the inspection.

[0044] 7 shows in more detail a geometric profile sensor 10 according to an embodiment of the invention. Each geometric profile sensor 10 consists of a rod 11 having a first side that is articulated directly to the frame 1 or to the geometric sensor support 13, and a second side with a contact tip 12 that slides over the metal part surface under inspection when relative displacement occurs between the frame and the metal part.

[0045] A magnet 14 and a magnetometric sensor capable of measuring a magnetic field are arranged in the area of ​​a first side of the rod 11 in the region of the coupling with the frame 1. Preferably, the magnet 14 is attached to the rod and the magnetic sensor is attached to the frame 1 or to the geometric profile sensor support 13 where the coupling with the rod occurs.

[0046] These geometric profile sensors 10 serve to obtain data relating to the geometric shape of the metal part surface and its respective defects (eg, ovalization, dents, bending, warping, scaling, buckling, among others).

[0047] 7, the rod 11 of the geometric profile sensor is connected to the frame 1 or the geometric profile sensor support 13 at a connection region, and at least one spring (not shown) or a set of springs is connected to a first side of the rod 11 and the frame 1 or to a first side of the rod 11 and the geometric profile sensor support 13 to assist in positioning the contact tip 12 against the surface of the part to be inspected. The contact tip 12 is the free end of the rod 11.

[0048] In this embodiment of the invention shown in FIG. 7, the contact tip 12 includes a bearing rotatably coupled to the other side of the rod in order to reduce friction with the surface of the geometric profile sensor. As a result, when there is a relative displacement between the metal part and the inspection device, the bearing continuously rolls with low friction on the surface of the cylindrical part to be inspected, covering the entire segment to be inspected on that surface. Also, other elements that provide a better sliding on the surface to be inspected, similar to the bearing, may also be used in the contact tip 12.

[0049] An arrangement of a series of geometric profile sensors 10 regularly spaced on a geometric profile sensor support 13 allows these sensors 10 to traverse multiple points on the metal part surface under inspection, thus obtaining more information about the entire surface, as shown in Figure 8. The greater the number of sensors, the larger the portion of the surface that is evaluated, resulting in greater resolution, redundancy, and reliability of the inspection results.

[0050] Thus, the combination of the rod 11 coupled to the frame 1 with the aid of a spring and the contact tip 12 in the form of a bearing allows the contact tip 12 to slide easily over the surface of the metal part, following the changes in the shape of the surface of the metal part. In the case of a relative displacement between the frame 1 and the metal part, when the contact tip 12 of the sensor 10 encounters a geometric change on the part, such as a depression corresponding to a deformation, the tip 12 moves relative to the frame 1 or the geometric profile sensor support 13, causing the rod 11 to rotate at the articulation area with the frame 1 or the support 13, which movement causes a variation in the magnetic flux generated by the magnet and detected by the magnetic sensor. The spring coupled to the rod helps to move the rod so that it remains in contact with the metal part surface, regardless of the variations in the shape of the inspection surface of the part. Magnetic measuring sensors can be used, in particular magnetometric sensors such as Hall sensors, giant magnetoresistance (GMR) sensors and superconducting quantum interference device (SQUID) sensors. Preferably, the magnetic sensor is a Hall sensor powered by a direct current of 5 volts. The polarity of the response signal indicates the direction of change of the magnetic flux, in other words a downward movement of the rod 11, e.g. due to a surface indentation, will generate a negative response signal and an upward movement, e.g. due to a local protrusion, will generate a positive response signal. The polarity of the signal can be reversed according to the calibration and positioning of the magnetic sensor.

[0051] In a non-illustrated embodiment of the invention, a laser point or line sensor can be used as the geometric profile sensor 10. The laser sensor is attached directly to the frame 1 or to the geometric profile sensor support 13 and determines the geometrical variations of the surface to be inspected. The device of the invention may also include a combination of the simultaneous use of a laser point or line sensor and a sensor consisting of a rod 11 combined with a magnet and a magnetic sensor as the geometric profile sensor 10.

[0052] The geometric profile sensor 10 may also include an encoder (not shown) located near the contact tip 12, which is responsible for determining the specific longitudinal position of the measurements taken on the inspected part. This encoder functions similarly to an odometer and converts the corresponding movement of the linear displacement of the bearing into an electrical signal. In this way, it is possible to determine how far the bearing has moved relative to the end of the pipe (e.g., by calculating how many revolutions it has made), and thus to determine the longitudinal position of any changes in the surface shape of the pipe detected by the geometric profile sensor 10. The encoder sends the electrical signal to an interpretation and evaluation unit, which is described further below.

[0053] The encoder may be located on only one of the geometric profile sensors 10 used in the apparatus, in which case the encoder serves as a reference for the relative longitudinal displacement of all other sensors used in the apparatus, including the eddy current sensor 20. Alternatively, the encoder may be located on multiple geometric profile sensors 10 to provide redundancy in order to increase accuracy in locating detected shape changes.

[0054] In another aspect of the invention, a preferred embodiment eddy current sensor 20 of the invention is best shown in Figures 5 and 6. The eddy current sensors 20 have an articulated mechanical system that ensures that the sensor always remains flat and parallel to the inspection surface. Each sensor 20 includes a shoe 21 having at least two coils 22 attached to the shoe. Preferably, two sets of coils are used for each sensor 20. Each shoe 21 is attached to the frame 1 or to an eddy current sensor support 23 on the frame such that it is proximate to the metal part surface as it passes through the interior of the frame 1.

[0055] Furthermore, the eddy current sensor 20 may include supports and springs to prevent direct impact of the metal part on the coil, i.e. to ensure that impacts on obstacles occur away from the coil. The metal part to be inspected first contacts the eddy current sensor 20 at the level of the rubber base arranged to cushion the impact. The material of the support of the coil may be made of polycarbonate and the rubber base may be made of polyurethane. Polycarbonate is a plastic material that has high resistance to both impacts and temperature. Polyurethane has good wear resistance and operates at high temperatures. The sensors are arranged so that the offset between the sensors is close to two consecutive rows. Preferably, this displacement is smaller than the width of a single eddy current sensor 20.

[0056] When a relative displacement occurs between the metal part and the frame 1 of the device, each eddy current sensor 20 detects the interference between the primary and secondary magnetic fields generated by the coil and the magnetic field generated by the eddy currents induced in the metal part, over the entire length of the metal part corresponding to the position where the sensor is located. Providing a series of eddy current sensors 20 spaced circumferentially on the eddy current sensor support 23 allows these sensors 20 to evaluate various points (or points) all over the surface to be inspected on the metal part, as shown in FIG. 8, and thus obtain more information about the entire surface. The greater the number of sensors, the larger the inspected area of ​​the surface to be evaluated, and therefore the higher the resolution and reliability of the inspection results. As can be seen in FIGS. 1 to 4, the eddy current sensors 20 are distributed in circular rows with an offset between the "annularly adjacent" eddy current sensors of two successive rows. Each eddy current sensor is independently attached to an articulated arm. Ideally, the offset should be less than the width of the sensor to achieve higher resolution and maximize the inspected surface, as shown in the resulting graphs in FIGS.

[0057] As eddy current sensor 20, sensors operating in absolute, differential, pick-up and PEC (pulsed eddy current) configurations can be used, among others. Preferably, the eddy current sensor includes two ferrite core coils connected in differential mode so that the response is the signal difference between the coils that make up the sensor. With the coils 22 of the sensor having the same number of turns but opposite polarity, the magnetic field generated by both coils is of the same magnitude but opposite direction. With this arrangement, when the sensor is located in a homogeneous area, its response is "zero" since one coil cancels the effect of the other coil. When approaching a defect area, the coil 22 that first contacts the defect has a different impedance than the coils in the homogeneous area, resulting in the generation of a non-zero signal. This sensor arrangement (or sensor array) is widely used for the detection of pitting, cracks, microcracks and scratches due to its high sensitivity. It has been found that the use of a differential structure improves the detection of defects by providing a higher signal-to-noise ratio. Furthermore, the differential mode reduces the effects of lift-off and microstructural variations during inspection. Lift-off is a response signal generated by the approach or removal of the eddy current probe from the material under test. During inspection, the eddy current probe may fall off due to external factors such as vibration, generating a response signal that may interfere with defect identification.

[0058] The device of the present invention can be used to inspect the inside or outside surface of a hollow metal part having a closed cross section, or it can be used to inspect any surface of a hollow or open metal part, or the outside surface of a solid metal part, or even the top and bottom surfaces of a small metal part (e.g., a sheet). To enable these multiple applications of the device of the present invention, it is only necessary that the design of the frame 1 and / or the eddy current sensor support 23 and the geometric profile support 13 have a cross section that matches the cross section of the segment to be inspected in the metal part, e.g., circular, triangular, square, rectangular, hexagonal, etc., to allow the geometric profile sensor 10 to slide over the inspection surface and for the eddy current sensor 23 to get close enough to the inspection surface to measure the magnetic field generated at the surface by the induced eddy currents and the variations in said magnetic field.

[0059] In the embodiment of the invention shown in FIG. 11, the apparatus is configured to inspect the outer surface of a part having a cylindrical cross section, and the frame 1 and sensors 13, 23 are located on the outside of the metal part. However, in FIG. 12, the apparatus is configured to inspect the inner surface of a part having a cylindrical cross section, and when there is a relative displacement between the frame and the metal part, the frame and the respective sensors pass inside the metal part. In the illustrated embodiment of the invention in FIG. 13, the apparatus is configured to inspect the surface of a sheet metal part, and when there is a relative displacement between the frame and the metal part, the frame and the respective sensors pass above and below the metal part. If the metal part has a varying cross section or configuration, frames and / or supports of various configurations may be required to inspect the entire surface of the part.

[0060] Additionally, the apparatus of the present invention may be operated with the mounting position frame such that the metal part moves relative to the frame 1, or the metal part is held in the mounting position while the frame 1 and sensor are moved relative to the part being inspected.

[0061] The apparatus also includes an electromagnetic signal electronic multiplexing circuit that receives and processes in real time the signals acquired by the geometric profile sensor 10 and the eddy current sensor 20. The signals captured by the sensors are sent to this multiplexing circuit, which digitizes the acquired signals in real time for subsequent evaluation. An interpretation / evaluation unit receives the digitized and processed signals from the electronic multiplexing circuit and identifies defects on the metal part surface using specialized signal processing algorithms for the reconstruction, evaluation and automatic classification of defects. This electronic evaluation unit may be a computer; a data processing center; or any electronic unit capable of performing the evaluation of the acquired data, the reconstruction of an image showing the evaluated metal part surface including defects and all the defects identified by the sensors, and the evaluation and classification of the detected defects.

[0062] The magnetic sensors of the geometric profile sensors and the encoders are connected to an interpretation / evaluation unit, which is arranged to correlate the measurement results of each geometric profile sensor 10 and the encoder. The geometric profile sensors 10 are related to each other by a spatial coordinate base. Each geometric profile sensor has a working direction with a contribution. As a result, the interpretation / evaluation unit can calculate the relative spatial position of the contact tips 12 of each geometric profile sensor. Preferably, the interpretation / evaluation unit is configured to generate a two-dimensional or three-dimensional model representing the shape of the outer surface of the inspected metal part.

[0063] Each eddy current sensor 20 is connected to an interpretation / evaluation unit. Each eddy current sensor 20 is associated with a respective registered lateral reference position in the interpretation / evaluation unit. The interpretation / evaluation unit is configured to associate the measurement output of each eddy current sensor 20 with its respective lateral reference position and with the longitudinal position output generated by the encoder. The interpretation / evaluation unit is configured to provide a user with graphical results representing the output generated by the eddy current sensor 20 as a function of longitudinal position and lateral position using the lateral positions obtained from the respective reference positions of the eddy current sensors 20. Such results are shown in FIG. 9.

[0064] In the apparatus of the present invention, the frame 1 may be a rotating body that rotates both inwardly and outwardly relative to the surface of the part to be inspected. To provide this rotational motion, a motor is coupled to the frame 1, which is also controlled by the apparatus of the present invention.

[0065] A technical advantage of this rotating configuration is that by rotating the frame with the sensors, it is possible to reduce the number of eddy current sensor supports 23 and geometric profile sensor supports 13, and therefore the length of the inspection device. This also reduces the number of sensors used and the corresponding cost of the device. Another technical advantage of this rotating configuration is that the rotational movement of the sensors facilitates improved detection of defects and a higher signal-to-noise ratio in the detection.

[0066] Furthermore, if the frame is arranged inside the part to be inspected, it may be coupled to its own traction mechanism, similar to a robot, which is responsible for moving the frame inside the metal part. This robot has its own propulsion system with a remotely controlled motor, providing a longitudinal displacement of the frame 1 with the sensor inside the metal part. The longitudinal movement of the metal part performed by the robot may be combined with the rotational movement of the frame described above, so that the entire inner surface of the metal part can be inspected by the sensor of the device of the invention. In this way, more data from the metal part surface can be obtained by the device of the invention, which significantly improves the identification of defects in the part. In another embodiment of the invention using a rotating configuration of the frame, the rotation mechanism of the frame itself is responsible for the longitudinal displacement of the inspection device inside with respect to the part to be inspected. In this embodiment of the invention, the inspection device includes at one of its ends a rotating head, on which the frame with the sensor support is arranged. This rotating head is coupled to a motor that provides the rotational movement to this head. Furthermore, small wheels or bearings are mounted on the periphery of the device and are in contact with the interior of the part to be inspected at the outer surface of the device. In this manner, as the rotating head rotates one way or the other, the device of the invention glides forwards or backwards, with the aid of wheels or bearings, inside the part being inspected.

[0067] The invention also refers to a method of inspecting metal parts, implemented by the inspection device described herein. The method includes a step of first generating a relative displacement between the metal part to be inspected and the frame of the metal part inspection device. During this relative displacement, the contact tips 12 of the geometric profile sensors 10 move by sliding or rolling on the surface of the metal part under inspection, so that the magnetic sensors detect the magnetic flux generated by the magnets due to the movement of the articulation (or joint) of each geometric profile sensor 10 with the frame 1. During this movement, eddy currents are induced in the inspected segment of the metal part, and the eddy current sensors 20 measure the interference between the magnetic field generated by their coils and the magnetic field generated by the eddy currents induced in the inspected segment. The geometric profile sensors 10 and the eddy current sensors 20 transmit their analog measurements to an electromagnetic signal electronic multiplexing circuit.

[0068] An electromagnetic signal electronic multiplexing circuit converts the analog data captured by the sensors into digital data and sends it to an interpretation / evaluation unit that identifies defects on the metal part surface based on the signals acquired from the geometric profile sensor 10 and the eddy current sensor 20.

[0069] If a laser sensor, such as a geometric profile sensor, is used, such a sensor detects variations in the geometric shape of the surface of the segment to be inspected and transmits them to an interpretation / evaluation unit.

[0070] Signals indicative of variations in the geometry of the surface being inspected may be obtained simultaneously by a geometric profile sensor 10 including a laser sensor and a geometric profile sensor 10 including a magnetic sensor and a magnet.

[0071] The interpretation / evaluation unit also performs the steps of analyzing and standardizing the signals received from the electromagnetic signal electronic multiplexing circuit, visually reconstructing the defects by images, analyzing the defect parameters, and classifying the identified defects.

[0072] Identifying defects on the metal part surface includes identifying geometric shape (or geometric contour) defects on the metal part surface under inspection, particularly defects such as ovalization, eccentricity, dents, crushing, warping, scaling, and buckling, based on data obtained from the geometric profile sensor 10, and identifying superficial defects such as cracks, microcracks, scratches, bends, bumps, small dimension mass loss (or pitting or nodule defects) based on data obtained from the eddy current sensor 20.

[0073] The method allows a detailed inspection result to be generated by combining the data captured by both types of sensors: it is thus possible to reconstruct the surface of the inspected metal part, together with all the defects detected and their dimensions.

[0074] Examples of visual reconstructions of the structure of the surface of an inspected metal part, including defects identified based on the analysis of the data obtained, are shown in Figures 9 and 10. In the example shown in these figures, the outer surface of a tube-shaped part, called "Sample 0", is evaluated. This part shows a processing defect, the dimensions of which are identified in the table below. TIFF0007639141000001.tif129155

[0075] According to the above table, the types of defects were classified based on their shape and in relation to the axial direction of the tubular shaped part.

[0076] The left graph in Fig. 9 is a representative signal obtained for said five defects from the above table, reconstructed after processing in the interpretation / evaluation unit, where the z-axis represents the response amplitude of the signal and the xy-plane (x-position area) represents the inspection area of ​​the part. The right graph in Fig. 9 is a top-down view of the left graph, corresponding to the results of the part inspection, showing the five detected defects. The right xy-plane graph represents the inspected surface of the part.

[0077] FIG. 10 is a graph showing the results of various data processing steps during evaluation, reconstruction, and classification of the five defects shown in FIG. 9 according to an embodiment of the present invention. The first row of FIG. 10 shows the selection of the defects identified in FIG. 9 by drawing a white contour line along the edge of these defects. After the selection of the defects and tracing of the contour line, a characteristic curve is defined and represented as a black line on the defect in the second row of FIG. 10. The defects are then represented using only the contour line and the characteristic curve as shown in the third row of FIG. 10. The complete representation of the defects shown in the graph of FIG. 9 is very data-intensive since it contains a large amount of data and information. However, a significant amount of this data is not necessary for the identification of the defects. The apparatus and method of the present invention are able to extract defects based only on the information of the contour line and the characteristic curve of each defect. The extracted defects are shown in the third row of FIG. 10. The following characteristics of these defects are extracted from the contour line and the characteristic curve: length, width, depth, perimeter, and area.

[0078] Thus, the device and method addressed by the present invention allows detailed and real-time inspection of metal parts of various sizes and diameters in general, due to the availability and positioning of the sensors on the frame and / or support, covering the entire surface of the metal part to be inspected as relative displacement occurs between the frame and the metal part. Also, the rod 11 associated with the spring allows the device to be adjusted to metal parts of various diameters. The ability to adapt the frame and / or support to inspected parts of various shapes and cross sections gives great flexibility to the device and method addressed by the present invention.

[0079] By correlating the results of two different types of complementary sensors, the apparatus and method of the present invention makes it possible to identify various types of defects on the surface of a metal part, both resulting from defects in the shape and configuration of the surface of the metal part, as well as from cracks, fissures and mass loss (or mass defects), at any location on the surface of the metal part.

[0080] The use of eddy current sensor 20, which is capable of detecting very small defects, allows for greater accuracy in the inspection of metal part surfaces.

Claims

1. 1. An apparatus for inspecting the inner and / or outer surfaces of metal parts, comprising: - frame(1); - a plurality of geometric profile sensors (10) mounted at intervals on the frame (1) via at least one geometric profile sensor support (13); - a plurality of eddy current sensors (20) mounted at a distance from one another on the frame (1) via at least one eddy current sensor support (23) and facing the metal part surface to be inspected; by which, during operation of the device, there is a relative displacement between the frame (1) and the metal part to be inspected, an electromagnetic signal electronic multiplexing circuit that receives and processes in real time the signals acquired by the multiple geometric profile sensors (10) and eddy current sensors (20); and An interpretation / evaluation unit that receives the processed signals from the electromagnetic signal electronic multiplexing circuit and identifies defects on the surface of the metal part. An inspection device comprising:

2. 2. The inspection device according to claim 1, characterized in that at least one geometric profile sensor support (13) has a cross section which matches a cross section of the metal part segment under inspection.

3. At least some of the plurality of geometric profile sensors (10) are articulated to the frame (1); - a rod (11) whose first side is articulated either to the frame (1) or to the geometric profile sensor support (13) and whose second side is coupled to a contact tip (12); - a magnet attached to a first side of a rod (11) connected to the frame (1); Including, During the relative displacement between the metal part and the frame (1), the contact tip (12) of each geometric profile sensor (10) moves over the surface of the metal part under inspection.

3. The inspection device according to claim 1 or 2.

4. 4. The inspection device according to claim 1, wherein the bearing is rotatably coupled to the contact tip (12) of the geometric profile sensor (10), such that the bearing rotates along the entire length of the metal part surface segment under inspection.

5. 5. The inspection device according to claim 1, wherein at least some of the plurality of geometric profile sensors (10) are either point laser sensors or line laser sensors, and these laser sensors are coupled to either the frame (1) or a geometric profile sensor support (13).

6. 6. The inspection apparatus of claim 4 or 5, wherein each of the plurality of geometric profile sensors (10) further comprises an encoder coupled to the bearing, the encoder determining a longitudinal position of a measurement taken on the inspected metal part based on movement of the bearing over the inspected metal part surface and transmitting corresponding longitudinal position data of the measurement to the electromagnetic signal electronic multiplexing circuit.

7. 7. The inspection device according to claim 1, wherein at least one spring is coupled to a first side of each rod (11) and to one of the frame (1) or the geometric profile sensor support (13).

8. Each eddy current sensor (20) includes a shoe (21) and at least two coils (22) coupled to the shoe (21); Each shoe (21) is attached to either the frame (1) or the geometric shape sensor support (13) and is positioned adjacent to a metal part surface during relative displacement between the metal part and the frame (1); 8. An inspection device according to claim 1, characterized in that each eddy current sensor (20) measures the interference between the magnetic field generated by the coil (22) and the magnetic field generated by induced eddy currents in the metal part segment under inspection.

9. An inspection device as claimed in any one of claims 1 to 8, characterized in that the positioning and number of the multiple eddy current sensors (20) and multiple geometric profile sensors (10) used are determined based on a predetermined resolution and redundancy, and each of the multiple eddy current sensors (20) and multiple geometric profile sensors (10) is independently attached to an articulated arm.

10. 10. The inspection device according to claim 9, characterized in that the eddy current sensors (20) and the surface geometric profile sensors (10) are regularly distributed in at least two regions to define at least two rows, with an offset between adjacent sensors of two consecutive rows.

11. 11. The inspection device of claim 10, wherein the offset is less than the width of a single eddy current sensor (20).

12. 12. The inspection device according to claim 1, characterized in that an electromagnetic signal electronic multiplexing circuit converts the signals acquired from the plurality of geometric profile sensors (10) and the plurality of eddy current sensors (20) into digital signals and transmits them to an interpretation / evaluation unit, which analyzes and standardizes the signals, reconstructs defects, analyzes defect parameters and classifies identified defects.

13. A plurality of geometric profile sensors (10) for identifying geometric defects on a surface of a metal part under inspection; The eddy current sensor (20) identifies defects such as cracks, microcracks, scratches, and small size mass loss defects.

13. The inspection device according to claim 1, wherein the inspection device is a semiconductor laser.

14. An inspection device according to any one of the preceding claims, characterized in that the plurality of eddy current sensors (20) operate in one of the following configurations: absolute configuration, differential configuration, pick-up configuration, and pulsed eddy current (PEC) configuration.

15. 15. The inspection device according to claim 1, characterized in that the magnetic sensor of the surface geometric sensor is one of a Hall sensor, a Giant Magneto-Resistance (GMR) sensor and a Superconducting Quantum Interference Device (SQUID) sensor.

16. 16. The inspection device according to claim 1, comprising a plurality of rods coupled to a frame (1), each rod being coupled to a geometric profile sensor (10) and an eddy current sensor (20), the eddy current sensor (20) being arranged at an end of a contact (12) of the geometric profile sensor.

17. Inspection device according to any one of the preceding claims, characterised in that the frame (1) together with the sensor support (12, 23) is rotatable around the metal part to be inspected.

18. 18. An inspection device according to claim 17, characterized in that a motor is coupled to the frame (1) and drives the rotational movement of said frame (1).

19. Where the inspection device is adapted to inspect an inner surface of the part to be inspected, the device further comprises a plurality of wheels coupled to an outer surface of the device for sliding on an inner surface of the part to be inspected; - the rotational movement of the frame (1) driven by said motor causes a longitudinal movement of the inspection device on the inner surface of the part to be inspected; 20. The inspection device according to claim 18,

20. An inspection device according to any one of the preceding claims, characterised in that the frame (1) is connected to a traction mechanism which moves the frame inside the metal part to be inspected.

21. A method for inspecting a surface of a metal part, the method being carried out by a device as defined in any one of claims 1 to 20, comprising the steps of: carrying out a relative displacement between the frame (1) of the device and the metal part to be inspected, and during said displacement; identifying defects in the geometric shape of the inspected surface of the part based on data acquired by the plurality of geometric profile sensors; and Identifying surface defects based on data acquired by a plurality of eddy current sensors (20). A method comprising:

22. During the relative displacement between the frame (1) of the device and the metal part to be inspected, a.1) a plurality of geometric profile sensors (10) acquiring measurements on the geometric shape of a metal part segment under inspection; a.2) Eddy currents are induced in the metal part segment under inspection; a.3) A number of eddy current sensors (20) measure the interference between the magnetic field generated by the coil and the magnetic field generated by the induced eddy currents in the segment to be inspected. a.4) the plurality of geometric profile sensors (10) and the plurality of eddy current sensors (20) transmit their analog measurement results to an electromagnetic signal electronic multiplexing circuit; b) the electromagnetic signal electronic multiplexing circuit converts the analog data captured in step a.4) into digital data and transmits them to an interpretation / evaluation unit; c) an interpretation / evaluation unit for identifying defects on the surface of the metal part based on the signals acquired from the plurality of geometric profile sensors (10) and the plurality of eddy current sensors (20); 22. The method according to claim 21 .

23. 23. The method according to claim 22, characterized in that in step a.1), the contact tips (12) of some of the plurality of geometric profile sensors (10) are moved over the surface of the metal part under inspection, and during this displacement, a magnetic sensor detects the magnetic flux generated by a magnet while the joint between the respective geometric profile sensor (10) and the frame (1) is moving.

24. A method for inspecting metal parts according to claim 22 or 23, characterized in that in step a.1), a laser sensor determines changes in the geometric shape of the metal part segment under inspection and transmits the obtained measurement results directly to an interpretation / evaluation unit.

25. Method according to any one of claims 22 to 24, characterized in that the interpretation / evaluation unit analyses and standardizes the signals received from the electromagnetic signal electronic multiplexing circuit, reconstructs the defects, analyzes the defect parameters and classifies the identified defects.

26. 26. The method according to any one of claims 21 to 25, characterized in that the surface defects include cracks, microcracks, scratches, bends and bumps, and the geometric defects include ovalization, eccentricity, dents, crushing, warping, scaling and buckling.

27. Implementing a relative displacement between the frame (1) of the device and the metal part to be inspected, - moving the metal part inside the frame (1) of the device in order to inspect its outer surface; - moving the frame (1) of the device outside the metal part in order to inspect the outer surface of the metal part; - moving the metal parts outside the frame (1) of the device in order to inspect their internal surfaces; and - moving the frame (1) of the device inside the metal part in order to inspect the inner surface of the metal part; The method according to any one of claims 21 to 26, characterized in that it comprises any one of the following:

Images