Electromagnetic ultrasonic double-wave transducer for detecting residual stress of pipeline

Abstract

The invention relates to the technical field of industrial detection, in particular to an electromagnetic ultrasonic double-wave transducer for detecting residual stress of a pipeline. The problems that in the prior art, single-wave detection errors are large, the fitting degree of a sensor and a pipeline curved surface is poor, and impact force affects an internal structure are solved. The invention provides an electromagnetic ultrasonic double-wave transducer. The electromagnetic ultrasonic double-wave transducer comprises a shell, a magnet assembly, a coil and other components. The magnet assembly is composed of a transversely-arranged first magnet, a longitudinally-symmetrical second magnet and a longitudinally-symmetrical third magnet, the included angle between the magnets is adjusted through a hinge, and vertical and horizontal magnetic fields are formed to excite transverse waves and longitudinal waves at the same time. The lower portion of the shell is arc-shaped and attached to the curved surface of the pipeline, and an elastic supporting structure and a flexible buffering layer are arranged at the joint to buffer impact force. In addition, a grounding lead is arranged to improve the signal-to-noise ratio. Through multi-magnet combination, the arc-shaped shell and the grounding wire buffer design, the magnetic field uniformity and the detection signal strength are effectively improved, and transverse and longitudinal wave integrated high-precision residual stress detection is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial non-destructive testing, and particularly to an electromagnetic ultrasonic dual-wave transducer for pipeline residual stress detection. Technical Background

[0002] In the safety assessment of industrial pipelines, the accurate detection of residual stress is crucial. Traditional electromagnetic ultrasonic detection technologies mostly use a single waveform (shear wave or longitudinal wave) for stress analysis. However, the detection method of a single waveform is easily affected by material anisotropy, environmental noise, and probe coupling state, resulting in large measurement errors. Specifically, shear waves are sensitive to surface stress but are easily interfered by the curvature of the pipeline, while longitudinal waves have a better response to deep stress, but their signal intensity is weak and they are easily affected by uneven magnetic field distribution.

[0003] However, the existing technologies have the following deficiencies: First, although the detection performance of a single waveform has been improved by optimizing the magnet arrangement or coil design, it is still impossible to balance the dual-wave collaborative excitation and signal stability, resulting in large errors in residual stress analysis; Second, the traditional transducer structure has strong rigidity, and the matching degree between its housing design and the pipeline curved surface is low, and the contact is insufficient, resulting in signal attenuation; Third, the magnet assembly lacks a dynamic buffering mechanism, and the impact force generated during the probe adsorption process is likely to damage the internal structural stability, causing the coil and the magnetic field center position to shift. These problems seriously restrict the application of electromagnetic ultrasonic technology in the high-precision detection of pipeline residual stress. Summary of the Invention

[0004] The purpose of the present invention is to provide an electromagnetic ultrasonic dual-wave transducer for detecting pipeline residual stress to solve the problem of large errors existing in the prior art when using a single wave for detection;

[0005] To achieve the above invention purpose, an embodiment of the present invention provides an electromagnetic ultrasonic dual-wave transducer for detecting pipeline residual stress, including a housing and a magnet and a coil arranged inside the housing. The coil is arranged below the magnet and is parallel to the bottom plane of the magnet. A wiring port connecting the probe and the control module is arranged at the central position of the upper part of the housing, and the wiring port is electrically connected to the coil;

[0006] As a further improvement of an embodiment of the present invention, it further includes a grounding wire arranged inside the housing and connected to the neutral wire inside the wiring port, and the other end of the grounding wire is connected to the probe housing;

[0007] As a further improvement of an embodiment of the present invention, the grounding wire is 1 - 10 wires;

[0008] As a further improvement of an embodiment of the present invention, the housing includes an upper housing in the shape of a cuboid and a lower housing with a certain arc at the bottom. The magnet is arranged inside the housing, and the coil and the buffer layer are arranged inside the lower housing;

[0009] As a further improvement of an embodiment of the present invention, a support structure with a support and buffer function is provided at the connection between the upper housing and the lower housing;

[0010] As a further improvement of an embodiment of the present invention, the support structure is an elastic material with a height of 0.5 - 1.5 mm;

[0011] As a further improvement of an embodiment of the present invention, three cube magnets are placed inside the upper housing. The first magnet is placed horizontally in the middle inside, and the second and third magnets are placed longitudinally on both sides of the first magnet;

[0012] As a further improvement of an embodiment of the present invention, inner shells are sleeved outside the first, second, and third magnets;

[0013] As a further improvement of an embodiment of the present invention, a clamping structure for supporting and fixing the inner shell is arranged on the inner wall of the housing;

[0014] As a further improvement of an embodiment of the present invention, fixed hinges exist between the inner shell of the second magnet and the inner shells of the first magnet and the third magnet, enabling a small angular change between the first magnet and the third magnet and the first magnet.

[0015] As a further improvement of an embodiment of the present invention, the fixed hinge is made of a non - magnetic material;

[0016] As a further improvement of an embodiment of the present invention, a flexible magnetic isolation plate is further included and arranged inside the housing. The flexible magnetic isolation plate is arranged between the inner shell and the coil and is coaxially arranged with the first magnet;

[0017] As a further improvement of an embodiment of the present invention, a buffer layer is further arranged below the coil. The buffer layer is arranged below the wire and contacts the surface of the metal to be measured;

[0018] As a further improvement of an embodiment of the present invention, the buffer layer is a flexible material with a thickness of 1 - 2 mm;

[0019] The beneficial effects of the present invention are as follows: The present invention adopts a combination of three magnets to form a non-uniform bias magnetic field, which can simultaneously excite transverse waves and longitudinal waves. The design of the bottom of the arc-shaped lower shell and the fixed hinges of the three magnets avoids the influence of the non-fitting between the pipe surface and the bottom of the probe on the test and the impact force during probe adsorption on the internal structure of the probe, improving the test performance of the electromagnetic ultrasonic sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 FIG. is a schematic structural diagram of an electromagnetic ultrasonic dual-wave transducer for detecting pipeline residual stress in an embodiment of the present invention;

[0021] Figure 2 is Figure 1 a schematic side sectional view of the structure in.

[0022] 1. Shell; 11. Upper shell; 12. Lower shell; 2. Inner housing; 21. Magnet fixing device; 22. Hinge; 3. Magnetic isolation part; 4. Coil; 5. Support structure; 6. Wire; 61. Ground wire; 62. Coil wire; 7. Wiring port; 8. Buffer layer; 9. Magnet; 91. First magnet; 92. Second magnet; 93. Third magnet; DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0024] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0025] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying 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 construed as a limitation of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and should not be construed as indicating or implying relative importance.

[0026] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installation", "connection", and "coupling" 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 directly connected or indirectly connected through an intermediate medium, and it can also be the communication inside two components. It can be a wireless connection or a wired connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] Moreover, it should be understood that although the terms first, second, etc. can be used in this document to describe various elements or structures, the objects described should not be limited by these terms. These terms are only used to distinguish these described objects from each other. For example, the first can be called the second magnet, and similarly the second magnet can also be called the first magnet, which does not deviate from the protection scope of this application.

[0028] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0029] In this embodiment, an electromagnetic ultrasonic dual-wave transducer for detecting pipeline residual stress is provided, which includes a housing and a magnet assembly and a coil disposed inside the housing. The coil is located below the magnet and is coaxially arranged with the magnet. A wiring port communicating with the inside of the housing is inlaid at the center above the housing, and the wiring port is electrically connected to the coil; along the direction from the magnet to the coil, the side surface of the housing shows an outward trend, and a zero line connected to the housing is provided at the wiring port as a grounding wire.

[0030] As shown in the figure, the electromagnetic ultrasonic dual-wave transducer provided in this embodiment includes a housing 1, an embedded wiring port 7, and a magnet assembly 9, a magnetic isolation member 3, a coil 4 disposed inside the housing 1, and a self-designed buffer structure 5.

[0031] Specifically, the first magnet 91, the second magnet 92, and the third magnet 93 are permanent magnets or electromagnets. In this embodiment, permanent magnets are taken as an example for illustration.

[0032] More specifically, the first magnet 91, the second magnet 92, and the third magnet 93 are solid permanent magnets in the shape of a cuboid. Among them, the vertically placed second magnet 92 and the vertically placed third magnet 93 provide a vertical magnetic field, and the horizontally placed first magnet 91 provides a horizontal magnetic field, so as to achieve the purpose of generating ultrasonic waves combining transverse and longitudinal waves in the workpiece to be measured.

[0033] At the same time, an outer shell 21 made of PLA is sleeved outside the three permanent magnets. While facilitating the connection between the magnets, it will not affect the distribution and intensity of the static magnetic field, and is connected through a hinge 22 to achieve the purpose of adjusting the angles of the second permanent magnet 92 and the third permanent magnet 93.

[0034] Of course, the hinge 22 is made of non-magnetic material and will not affect the static magnetic field generated by the magnet assembly.

[0035] At the same time, a clamping structure for supporting and fixing the first magnet 91 is arranged on the inner wall of the outer shell.

[0036] The coil 4 of the electromagnetic ultrasonic sensor provided in this embodiment is arranged below the magnet assembly 9. At the same time, a flexible magnetic isolation plate 3 is arranged between the magnet assembly 9 and the coil 4, and the magnet assembly 9, the flexible magnetic isolation plate 3 and the coil 4 are coaxially arranged. A buffer material 8 is arranged below the coil 4 to buffer the impact force and improve the fit with the pipeline to be measured; when using this electromagnetic ultrasonic sensor to measure the pipeline stress, an alternating signal of high-frequency current passes through the coil, generating eddy currents on the surface of the workpiece to be measured. The eddy currents are affected by the static magnetic field generated by the magnet assembly, generating Lorentz force, and thus generating transverse waves and longitudinal waves simultaneously.

[0037] Specifically, the outer diameter of the coil 4 should be smaller than the length of the magnet assembly 9.

[0038] More specifically, the outer diameter of the coil 4 should be smaller than the length of the magnetic conduction sheet 3, and the difference between the outer diameter of the coil 4 and the length of the magnetic conduction sheet 3 should be less than 1 mm. That is, in this embodiment, the magnetic conduction sheet 3 and the coil 4 can be regarded as a whole.

[0039] At the same time, in order to make the coil generate a stronger high-frequency signal, this embodiment adopts a racetrack-shaped coil or a spiral-shaped coil, and according to λ = 2L, the wire pitch of the coil below the first magnet 91 that generates longitudinal waves is set to half of the wavelength of the longitudinal wave excited, and the wire pitch of the coil below the second magnet 92 and the third magnet 93 that generate transverse waves is set to half of the wavelength of the transverse wave excited.

[0040] Of course, in other embodiments, the coil of the electromagnetic ultrasonic sensor can also adopt a hollow coil, as long as the outer diameter of the hollow coil is smaller than the outer diameter of the first magnet.

[0041] A wiring port 7 is inlaid above the outer shell 11. The coil 4 is connected to the external power supply through a wire 62 and the wiring port 7. The wiring port is inlaid inside the upper shell of the outer shell 11. While facilitating the connection of external devices, it avoids damage to the plug due to excessive bending. The neutral wire 61 inside the wiring port is connected to the external shell 11 to achieve the grounding function and ensure the reliability of the electrical connection. The grounding wire 61 can be composed of 1 - 10 wires to improve the grounding effect.

[0042] Furthermore, a wiring port 7 is provided at the center of the upper shell of the outer shell 11. At the same time, this patent makes an innovation in the structural design of the wiring port. The wiring port 7 is embedded inside the shell. While facilitating connection, it avoids damage to the external connection device caused by excessive bending, and also improves the integrity and aesthetics of the external structure of the probe. The coil 4 is electrically connected to the plug connector 7 through a wire 62.

[0043] Specifically, the outer shell 1 includes an upper outer shell 11 in the shape of a cuboid and a lower outer shell 12 with a certain arc at the bottom. The magnet assembly 9 is arranged inside the upper outer shell 11, and the coil 4 and the buffer layer 8 are arranged inside the lower outer shell.

[0044] At the same time, a support structure 5 with a support and buffering function is provided at the connection between the upper outer shell 11 and the lower outer shell 12, greatly reducing the possibility of structural damage to the probe during use. A support structure 8 with a support and buffering function is also provided between the lower outer shell 12 and the object to be measured, improving the fit between the probe and the measured part, making the generated magnetic field more suitable for the shape of the measured part, and thus improving the measurement accuracy.

[0045] Specifically, the buffer structure 5 provided at the connection between the upper outer shell 11 and the lower outer shell 12 is a spring washer.

[0046] Specifically, the support structure 8 provided between the lower outer shell 12 and the object to be measured is an elastic material with a height of 0.5 - 1.5 mm.

[0047] It should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0048] The series of detailed descriptions listed above are only specific descriptions of the feasible embodiments of the present invention, and they are not intended to limit the protection scope of the present invention. Any equivalent embodiments or modifications made without departing from the technical spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. An electromagnetic ultrasonic dual-wave transducer for detecting the residual stress of a pipeline, characterized in that, It includes a housing, a magnet and a coil disposed within the housing. The coil is disposed below the magnet and parallel to the bottom plane of the magnet. An interface is provided at the center of the upper part of the housing to communicate with the interior of the housing, and the interface is electrically connected to the coil.

2. The housing includes an upper housing in the shape of a cuboid and a lower housing with a curved bottom. The magnet is disposed within the upper housing, and the coil and the buffer layer are disposed within the lower housing.

3. The magnet includes three cubic magnets. The first magnet is horizontally placed in the middle of the interior of the upper housing. The second magnet and the third magnet are vertically placed on both sides of the first magnet. The first magnet is connected to the second magnet and the third magnet by a fixed hinge made of non-magnetic material to change the included angle between the magnets. The rotation angle range of the fixed hinge is 0°-15° to adapt to the detection requirements of different pipe diameters.

4. A clamping structure is provided on the inner wall of the housing for supporting and fixing the first magnet.

5. The transducer further includes a flexible magnetic isolation plate, which is disposed between the magnet and the coil and coaxially arranged with the first magnet.

6. The electromagnetic ultrasonic dual-wave transducer according to claim 1, wherein It further includes a grounding wire, which is disposed inside the housing and connected to the neutral wire inside the interface. The other end of the grounding wire is in contact with the upper housing, and the grounding wire is composed of 1-10 wires.

7. The electromagnetic ultrasonic dual-wave transducer according to claim 1, wherein A support structure is provided at the connection between the upper housing and the lower housing. The support structure is an elastic material with a height of 0.5-1.5 mm for buffering the impact force at the connection of the housing.

8. The electromagnetic ultrasonic dual-wave transducer according to claim 1, characterized in that, The bottom curvature of the lower housing approximately matches the outer surface curvature of the pipeline to be measured, and the lowermost buffer layer is a flexible material with a thickness of 1-2 mm.

9. The electromagnetic ultrasonic dual-wave transducer according to claim 1, characterized in that, The clamping structure is a convex structure symmetrically distributed on the inner wall of the upper housing, and the convex structure is in close contact with the side surface of the first magnet.

10. The electromagnetic ultrasonic dual-wave transducer according to claim 1, characterized in that, The coil is a multi-layer winding structure, the difference between its outer diameter and the outer diameter of the magnet assembly is less than 2 mm, and it is connected to the interface through a high-frequency shielded cable.

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