A Separate ACFM Crack Detection Probe

Abstract

The present invention discloses a separate ACFM crack detection probe, including an upper top shell, a middle upper connection shell, a middle lower installation shell and a lower bottom shell connected to each other; the top shell includes a top shell body and a sealed aviation plug interface connected thereto; the connection shell includes a connection shell body and three signal conditioning modules arranged on its inner wall; the installation shell includes an installation shell body and a magnetic core, a copper wire winding and a covering shell of the magnetic core winding arranged therein; the bottom shell includes a bottom shell body and a sensor arranged at its end. Not only is it highly convenient in installation and molding, but it is also conducive to the detection of complex environments, and is highly efficient in maintenance and troubleshooting. The upper and lower distribution of sensors and signal conditioning modules avoids electromagnetic interference to a certain extent, thereby improving the detection accuracy.

Description

Technical Field

[0001] The invention relates to a nondestructive testing technology, in particular to a separated ACFM crack detection probe, which is particularly suitable for surface crack detection of metal structures. Background Art

[0002] Alternating current field measurement (ACFM) technology is a practical nondestructive testing technology in recent years. It combines the characteristics of eddy current testing, electromagnetic induction and skin effect. It uses medium and high frequency excitation coils to induce uniform current on the metal surface. Due to the skin effect, the current gathers on the crack surface. At the crack, due to the resistivity difference, the induced current is distributed at the end point, causing irregular distribution of the spatial magnetic field. By detecting the distorted magnetic field above the crack, the distribution characteristics of the surface crack can be further obtained after analysis. ACFM technology solves the problems of lack of practicality and complex operation in eddy current testing, has been widely used, and has derived rotating probes and array multi-probe engineering technologies. With the continuous development and improvement of this technology, there have been actual industrial applications and research in fields such as marine equipment and manufacturing.

[0003] However, with the diversification of applications, the interrelationships between internal components have become increasingly complex, which in turn places higher requirements on detection probes, and detection probes in the prior art are difficult to meet the requirements.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The purpose of the present invention is to provide a separate ACFM crack detection probe to solve the above technical problems existing in the prior art.

[0006] The objective of the present invention is achieved through the following technical solutions:

[0007] The separate ACFM crack detection probe of the present invention comprises an upper top shell, a middle upper connection shell, a middle lower installation shell and a lower bottom shell which are interconnected;

[0008] The top shell comprises a top shell body 1 and a sealed 12-core aviation plug interface 2 connected thereto;

[0009] The connection shell includes a connection shell body 3 and three signal conditioning modules 4, 5, 6 arranged on the inner wall thereof;

[0010] The installation shell comprises an installation shell body 7 and a magnetic core 8, a copper wire winding 9, and a covering shell 10 of the magnetic core winding arranged inside the installation shell;

[0011] The bottom case includes a bottom case body 11 and a sensor 12 disposed at an end thereof.

[0012] Compared with the prior art, the separate ACFM crack detection probe provided by the present invention is not only more convenient in installation and molding, but also conducive to detection in complex environments, and has higher efficiency in maintenance and problem troubleshooting. The upper and lower distribution of the sensor and signal conditioning module avoids electromagnetic interference to a certain extent, thereby improving the detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A schematic diagram of the structure of a separate ACFM crack detection probe provided by an embodiment of the present invention;

[0014] Figure 2a , Figure 2b They are schematic diagrams of power supply line connection of the lower bottom shell and the middle connecting shell in the embodiments of the present invention;

[0015] Figure 3 This is a schematic diagram of the circuit connection of the middle installation shell in an embodiment of the present invention;

[0016] Figure 4 This is a schematic diagram of the circuit connection between the middle connecting shell and the lower bottom shell in an embodiment of the present invention;

[0017] In the figure:

[0018] 1. Top shell body; 2. Aviation plug interface; 3. Connection shell body; 4. Signal conditioning module; 5. Signal conditioning module; 6. Signal conditioning module; 7. Mounting shell body; 8. Magnetic core; 9. Copper wire winding; 10. Covering shell of magnetic core winding; 11. Bottom shell body; 12. Sensor; 13. Sealing groove; 14. Sealing groove; 15. Sealing groove; 16. Clamping screw; 17. Sensor power supply; 18. Signal conditioning module power supply; 19. Power amplifier type excitation source; 20. Second-order RC low-pass filter; 21. AD620 chip; 22. Signal acquisition device. DETAILED DESCRIPTION

[0019] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, not all of the embodiments, which does not constitute a limitation of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] First, the terms that may be used in this article are explained as follows:

[0021] The term “and / or” means that either or both of them can be realized at the same time. For example, X and / or Y means both “X” or “Y” and “X and Y”.

[0022] The terms "include", "comprises", "contains", "has" or other descriptions with similar semantics should be interpreted as non-exclusive inclusion. For example, including certain technical feature elements (such as raw materials, components, ingredients, carriers, dosage forms, materials, dimensions, parts, components, mechanisms, devices, steps, procedures, methods, reaction conditions, processing conditions, parameters, algorithms, signals, data, products or products, etc.) should be interpreted as including not only certain technical feature elements explicitly listed, but also other technical feature elements known in the art that are not explicitly listed.

[0023] The term "consisting of..." means excluding any technical feature elements not explicitly listed. If this term is used in a claim, it will make the claim closed, so that it does not include technical feature elements other than those explicitly listed, except for conventional features related to them. If this term only appears in a clause of a claim, it only limits the elements explicitly listed in that clause, and the elements recorded in other clauses are not excluded from the overall claim.

[0024] Unless otherwise specified or limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this article can be understood according to specific circumstances.

[0025] The orientation or position relationship indicated by terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc. are based on the orientation or position relationship shown in the drawings and are only for the convenience and simplification of description, and do not explicitly or implicitly indicate that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation of this document.

[0026] The contents not described in detail in the examples of the present invention belong to the prior art known to professionals in the field. If no specific conditions are specified in the examples of the present invention, the conditions are carried out according to the conventional conditions in the field or the conditions recommended by the manufacturer. If the manufacturer is not specified in the reagents or instruments used in the examples of the present invention, they are all conventional products that can be purchased commercially.

[0027] The separate ACFM crack detection probe of the present invention comprises an upper top shell, a middle upper connection shell, a middle lower installation shell and a lower bottom shell which are interconnected;

[0028] The top shell comprises a top shell body 1 and a sealed 12-core aviation plug interface 2 connected thereto;

[0029] The connection shell includes a connection shell body 3 and three signal conditioning modules 4, 5, 6 arranged on the inner wall thereof;

[0030] The installation shell comprises an installation shell body 7 and a magnetic core 8, a copper wire winding 9, and a covering shell 10 of the magnetic core winding arranged inside the installation shell;

[0031] The bottom case includes a bottom case body 11 and a sensor 12 disposed at an end thereof.

[0032] The top shell body 1 and the aviation plug interface 2 are internally sealed using an O-ring, and the connection method is a threaded connection.

[0033] The positive and negative power supply lines of the signal conditioning module led out from the aviation plug interface 2 are connected to the positive and negative power supply input terminals of the signal conditioning module 4, the positive and negative power supply output terminals of the signal conditioning module 4 are connected to the positive and negative power supply input terminals of the signal conditioning module 5, and the positive and negative power supply output terminals of the signal conditioning module 5 are connected to the positive and negative power supply input terminals of the signal conditioning module 6.

[0034] The positive and negative power supply lines of the sinusoidal excitation led out from the aviation plug interface 2 are connected to the copper wire taps at both ends of the copper wire winding 9;

[0035] The covering shell 10 of the magnetic core winding is connected to the mounting shell body 7 by bolts, and the unwound parts of the magnetic core 8 at both ends are clamped in the middle. The diagonal of the covering shell 10 is designed with wiring holes for the excitation coil. The diameter of the covering groove in the covering shell 10 is wider in the middle winding part than in the unwound parts at both ends.

[0036] The magnetic core 8 is made of nickel-zinc ferrite.

[0037] A groove is arranged in the middle of the bottom shell body 11 and a sensor 12 is placed therein;

[0038] The bottom shell body 11 has a wall thickness of 1 mm and is made of nylon;

[0039] The scanning direction of the X end of the sensor 12 is parallel to the wide side wall of the bottom shell body 11;

[0040] The positive and negative power supply terminals of the sensor 12 are connected to the positive and negative power supply wires of the sensor 12 led out from the aviation plug interface 2;

[0041] The three differential voltage output signals of the sensor 12 are respectively connected to the signal input terminals of the three signal conditioning modules 4, 5, and 6;

[0042] The signal output ends of the signal conditioning modules 4 , 5 , and 6 are connected to the signal output interface of the aviation plug interface 2 .

[0043] The joints of the top shell body 1, the connecting shell body 3, the mounting shell body 7 and the bottom shell body 11 are all designed with sealing grooves 13, 14, 15, which are sealed with O-rings and connected by bolts;

[0044] A compression nut 16 is designed between the top shell body 1 and the aviation plug interface 2 to compress the O-ring.

[0045] Used to detect surface cracks on magnetic metal structures.

[0046] From the above, it can be seen that the separated ACFM crack detection probe of the embodiment of the present invention mainly includes four parts: the upper top shell, the middle connecting shell, the middle installation shell and the lower bottom shell. The upper top shell mainly transmits 12 lines through the aviation plug interface, including the positive and negative input interface of the excitation signal, the output interface of the three types of differential voltage signals, the positive and negative power supply interface of the signal conditioning module and the positive and negative power supply interface of the TMR sensor; the middle connecting shell is mainly responsible for carrying the signal conditioning plate, which is mainly responsible for the amplification and filtering of the three types of voltage analog signals, and the bearing method is strong adhesive fixation of the side wall; the middle installation shell is designed with a mounting seat for fixing the magnetic core winding, and the upper covering shell of the magnetic core winding has a wiring hole; the lower bottom shell is used to install the sensor. The four shells are connected internally. This kind of probe is not only highly convenient in installation and molding, but also conducive to the detection of complex environments. It is more efficient in maintenance and troubleshooting. The upper and lower distribution of the sensor and the signal conditioning module avoids a certain degree of electromagnetic interference and improves the detection accuracy.

[0047] The present invention can realize effective detection of the probe in multiple complex environments, ensure the stability and consistency of the detection process, improve the detection flexibility and efficiency, and reduce labor intensity. Its beneficial technical effects are:

[0048] 1. The present invention improves the efficiency of probe installation and maintenance by designing a separate multi-functional shell probe.

[0049] 2. The present invention reduces the loss of weak voltage signals by providing a built-in signal conditioning module; and designs a three-way separate signal conditioning module, which can separately condition the voltage signals in the X, Y and Z directions, thereby avoiding interference between signals.

[0050] 3. The present invention designs a cylindrical magnetic core made of nickel-zinc ferrite, which meets the application conditions of medium and high frequency electromagnetic fields and reduces electromagnetic losses.

[0051] 4. In the present invention, a fixing groove for a sealing ring is designed between each shell of the probe, which is conducive to the detection scenario of both water and land.

[0052] 5. The separate design of the probe in the present invention minimizes the signal interference between the various components.

[0053] 6. The present invention has a simple structure, high practicability and is conducive to detection in narrow and complex environments.

[0054] In order to more clearly demonstrate the technical solution and technical effects provided by the present invention, the contents provided by the embodiments of the present invention are described in detail with specific embodiments below.

[0055] Example 1

[0056] like Figures 1 to 4 As shown:

[0057] like Figure 1 As shown, a separate ACFM crack detection probe provided by the present invention includes four parts: an upper top shell, a middle connecting shell, a middle mounting shell and a lower bottom shell. The top shell part mainly includes a top shell body 1 and a sealed aviation plug interface 2 connected thereto; the connecting shell part includes a connecting shell body 3 and three signal conditioning modules 4, 5 and 6; the mounting shell part includes a mounting shell body 7, a magnetic core 8, a copper wire winding 9 and a covering shell 10 for the magnetic core winding, and the bottom shell part includes a bottom shell body 11 and a sensor 12. The connection parts of the four parts, the upper top shell body 1, the middle connecting shell body 3, the middle mounting shell body 7 and the lower bottom shell body 11, are all designed with sealing grooves 13, 14 and 15, and the connection part between the upper top shell body 1 and the aviation plug interface 2 is designed with a clamping nut 16 for fixing the O-ring.

[0058] During the crack detection of metal structures, the probe is perpendicular to the surface of the structure, specifically the bottom surface of the bottom shell body 11 is parallel to the surface of the structure, and the lift-off height is maintained at 2mm. The detection process always maintains this form, that is, translation scanning detection, with a speed of 10-30mm / s.

[0059] Before the detection begins, the power supply and signal line connections are completed. The detection process is to move the probe in a fixed direction (when detecting at a given crack, the X direction of the sensor 12 is parallel to the defect length direction to the greatest extent). During this process, the copper wire winding 9 excites an alternating magnetic field around it under the action of an external alternating excitation source. Under the action of the alternating magnetic field, the metal structure generates a skin current near the surface of the metal structure due to the skin effect. Under normal defect-free conditions, the direction of the skin current is perpendicular to the magnetic core 8; when there is a defect crack on the surface, the distribution of the skin current will be singular due to resistivity and other reasons, which is specifically manifested as current flowing around the two ends of the crack and interruption in the middle. Because of this singular distribution, the surrounding magnetic field signal will be distorted. At this time, the regular electromagnetic field signal originally excited by the magnetic core winding will mutate at a certain position due to this distortion. The signal curve obtained after the sensor 12 scans once can clearly show the singularity of the signal. The position and size characteristics of the defect crack can be determined by judging the singularity and the overall signal.

[0060] The specific power supply terminal connection method is as follows: the probe power supply terminal includes two parts: a three-axis sensor 12 and a signal conditioning module 4-6. The three-axis sensor 12 has eight pins, including a pair of positive and negative power supply terminals and three differential signal outputs of X, Y and Z. The external sensor power supply 17 is 1V, which passes through the corresponding end of the aviation plug interface 2, the connecting shell body 3 and the mounting shell body 7, and finally enters the bottom shell body 11, and is connected to the positive and negative power supply terminals of the sensor 12. Specifically, Figure 2a As shown. The signal conditioning modules 4-6 correspond to three differential signals respectively. The three signal conditioning modules 4-6 are all provided with differential signal input terminals, signal output terminals, positive and negative power supply terminals and power output terminals. The external signal conditioning module power supply 18 is 12V, which enters the connection shell body 3 through the corresponding terminal of the aviation plug interface 2 and the top shell body 1, and is connected to the positive and negative power supply terminals of the signal conditioning module 4. Then, the power output terminal of the signal conditioning module 4 is connected to the positive and negative power supply terminals of the signal conditioning module 5, and finally, the power output terminal of the signal conditioning module 5 is connected to the positive and negative power supply terminals of the signal conditioning module 6. The specific series connection method is as follows: Figure 2b As shown. At this point, the two parts of the power supply connection are completed.

[0061] The specific signal flow input direction is: the external power amplifier excitation source 19 inputs the sinusoidal alternating current through the corresponding end of the aviation plug interface 2, passes through the top shell body 1 and the connecting shell body 3, and finally transmits it to the installation shell body 7, and connects with the two taps of the copper wire winding 9, and continuously excites during the detection process. Figure 3 shown.

[0062] The specific signal flow output direction is: the voltage signals obtained in the X, Y and Z directions of the sensor 12 are transmitted through the bottom shell body 11 and the mounting shell body 7, and finally transmitted to the signal conditioning module 4-6 connected to the shell body 3. The function of this module is mainly to filter and amplify the signal, reduce the original interference and avoid voltage signal loss. The filtering method adopts a second-order RC low-pass filter 20, and the signal amplification circuit is built through the AD620 chip 21. After passing through the signal conditioning module 4-6, the output ends of the three differential signals are respectively connected to the corresponding ends of the aviation plug interface 2, and finally input into the host computer through the peripherally configured signal acquisition device 22. Specifically, Figure 4 shown.

[0063] In summary, the detection probe of the present invention can realize detection in narrow and complex environments, ensure the stability and effectiveness of detection, improve the flexibility and efficiency of detection, and reduce installation and maintenance costs.

[0064] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims. The information disclosed in the background technology section of this article is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as an admission or in any form that the information constitutes prior art known to those skilled in the art.

Claims

1. A separate ACFM crack detection probe, characterized in that: It includes an upper top shell, a middle upper connection shell, a middle lower installation shell and a lower bottom shell which are interconnected; The top shell comprises a top shell body (1) and a sealed 12-core aviation plug interface (2) connected thereto; The connection shell comprises a connection shell body (3) and three signal conditioning modules (4, 5, 6) arranged on the inner wall thereof; The installation shell comprises an installation shell body (7), a magnetic core (8), a copper wire winding (9), and a covering shell (10) of the magnetic core winding arranged inside the installation shell body; The bottom shell comprises a bottom shell body (11) and a sensor (12) arranged at an end thereof; The positive and negative power supply lines of the signal conditioning module led out of the aviation plug interface (2) are connected to the positive and negative power supply input terminals of the signal conditioning module (4), the positive and negative power supply output terminals of the signal conditioning module (4) are connected to the positive and negative power supply input terminals of the signal conditioning module (5), and the positive and negative power supply output terminals of the signal conditioning module (5) are connected to the positive and negative power supply input terminals of the signal conditioning module (6); The positive and negative sinusoidal excitation power supply lines led out of the aviation plug interface (2) are connected to the copper wire taps at both ends of the copper wire winding (9); the covering shell (10) of the magnetic core winding is connected to the mounting shell body (7) by bolts, and is responsible for clamping the unwound parts at both ends of the magnetic core (8); the diagonal of the covering shell (10) is designed with wiring holes for the excitation coil; the diameter of the covering groove of the covering shell (10) is wider in the middle winding part than in the unwound parts at both ends; the magnetic core (8) is made of nickel-zinc ferrite; A groove is arranged in the middle of the bottom shell body (11) and a sensor (12) is placed therein; the bottom shell body (11) has a wall thickness of 1 mm and is made of nylon; The scanning direction of the X end of the sensor (12) is parallel to the wide side wall of the bottom shell body (11); The positive and negative power supply ends of the sensor (12) are connected to the positive and negative power supply lines of the sensor (12) led out of the aviation plug interface (2); The three differential voltage output signals of the sensor (12) are respectively connected to the signal input ends of the three signal conditioning modules (4, 5, 6); The signal output end of the signal conditioning module (4, 5, 6) is connected to the signal output interface of the aviation plug interface (2).

2. The separate ACFM crack detection probe according to claim 1, characterized in that: The top shell body (1) and the aviation plug interface (2) are internally sealed using an O-ring, and the connection method is a threaded connection.

3. The separate ACFM crack detection probe according to claim 1 or 2, characterized in that: The connection points of the top shell body (1), the connecting shell body (3), the mounting shell body (7) and the bottom shell body (11) are all designed with sealing grooves (13, 14, 15) and are connected by bolts; A clamping nut (16) is designed between the top shell body (1) and the aviation plug interface (2) to clamp the O-ring.

4. The separate ACFM crack detection probe according to claim 3, characterized in that: Used to realize crack detection of magnetic metal structures.

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