Axle defect detection guided wave transducer and axle defect detection device

Abstract

The present invention provides an axle defect detection guided wave transducer and an axle defect detection device, which relate to the technical field of axle defect detection and include a flexible substrate, a permanent magnet, an upper coil and a lower coil; the flexible substrate is used to be fixed on the end circumferential wall surface of the axle; the permanent magnet is located above the flexible substrate, and the magnetic poles of two adjacent permanent magnets are opposite; the spacing between the two adjacent permanent magnets is equal to the wavelength of the guided wave; the upper coil and the lower coil are respectively arranged at the top and bottom of the flexible substrate, and both are in an oblique fold shape, and the oblique fold angle of the lower coil is complementary to the oblique fold angle of the upper coil; the direction of the current in the lower coil is opposite to the direction of the current in the upper coil; the present invention can increase the intensity of the excited ultrasonic signal by more than two times, so that the propagation distance of the sound wave is longer; and the guided wave transducer in the present invention can also reduce the width of the excited ultrasonic signal wave packet by half, so that the defect parameters are easier to quantify.

Description

Technical Field

[0001] The present invention relates to the technical field of axle defect detection, and in particular to an axle defect detection guided wave transducer and an axle defect detection device. Background Art

[0002] High-speed trains, as a vital means of transporting passengers and bulk cargo, embody the latest advances in rail transit technology. However, they often operate under harsh conditions such as high vibration, heavy loads, and high cycle times. The running gear, which directly drives the train, constantly faces extreme environments such as dust, heavy rain, high temperatures, and extreme cold, resulting in extremely complex operating conditions. Axles are key load-bearing components of high-speed train bogies, directly connecting the wheels and suspension. They not only provide the output of the gear transmission system but also, as a core component of the wheelset, bear the locomotive's deadweight and additional loads. However, axle journals are subject to long-term rotational bending and impact during service, making them highly susceptible to fatigue cracking. When cracks develop to a certain extent, the journals are susceptible to cold shearing under the effects of alternating stresses, leading to major train derailments. Therefore, research on highly sensitive online microcrack detection and quantitative safety assessment for rotating axles on in-service trains is a critical and pressing issue in the field of high-speed train safety inspection.

[0003] One detection technology the inventors are aware of utilizes contact-type piezoelectric ultrasonic transducers that rotate synchronously with a hollow axle to excite ultrasonic guided waves. By arranging and exciting the transducers around the entire circumference, the circumferential and axial acoustic field signals of axle surface defects are acquired, and the sensitivity of the guided waves to defect depth and length is discussed. However, the operating environment of high-speed trains is extremely harsh, with axles subjected to constant high-speed rotation and reciprocating vibration. Existing acoustic emission detection technologies rely heavily on complex denoising algorithms and crack signal feature extraction methods. These technologies are only sensitive to large cracks in the process of expansion and cannot effectively detect early fatigue microcracks.

[0004] Therefore, it is necessary to develop a new type of detection device to effectively detect cracks in axles and provide a new solution for the safety assessment of rotating components of high-speed trains. Summary of the Invention

[0005] The purpose of the present invention is to provide an axle defect detection guided wave transducer and an axle defect detection device to solve the problems existing in the prior art. It can increase the intensity of the excited ultrasonic signal by more than two times compared with the traditional runway coil transducer, so that the propagation distance of the sound wave is longer and the defect detection sensitivity is improved; it can also reduce the width of the excited ultrasonic signal wave packet by half, so that the equivalent length, width and depth index parameters of the defect are easier to quantify.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] A waveguide transducer for detecting defects in an axle comprises a flexible substrate, a permanent magnet, an upper coil and a lower coil; the flexible substrate is used to be fixed on the circumferential wall surface of the end of the axle; the permanent magnet is located above the flexible substrate and is arranged in a plurality of intervals, the magnetic poles of two adjacent permanent magnets are opposite; the spacing between two adjacent permanent magnets is equal to the wavelength of the waveguide; the upper coil is arranged on the top of the flexible substrate and below the permanent magnet, and along the extension direction of a single permanent magnet, the upper coil is in an oblique folded shape, and the spacing between the conductors in the oblique folded shape of the upper coil is equal to the wavelength of the waveguide; the lower coil is arranged The lower coil is arranged at the bottom of the flexible substrate, and along the extension direction of a single permanent magnet, the lower coil is in an oblique folded shape, the spacing of the conductors in the oblique folded shape of the lower coil is equal to the wavelength of the waveguide, and the oblique folding angle of the lower coil is complementary to the oblique folding angle of the upper coil; in the direction perpendicular to the surface of the flexible substrate, the upper coil and the lower coil overlap to form an overlapping area, and in the arrangement direction of the multiple permanent magnets, the distribution range of the overlapping area is larger than the distribution range of the multiple permanent magnets; in the extension direction of a single permanent magnet, the direction of the current in the lower coil is opposite to the direction of the current in the upper coil.

[0008] As an embodiment, the bending angle of the upper coil relative to the extension direction of the single permanent magnet is 45°, and the bending angle of the lower coil relative to the extension direction of the single permanent magnet is 135°.

[0009] As an embodiment, the ratio of the current in the upper coil to the current in the lower coil is adjustable.

[0010] As one embodiment, the distance between two adjacent permanent magnets is 16 mm.

[0011] In one embodiment, the width of a single permanent magnet is 4 mm to 6 mm.

[0012] As an embodiment, the radial cross-sectional area of ​​the conductors of the upper coil and the lower coil is the same, which is 0.2 mm. 2 ~0.5mm 2 .

[0013] As an embodiment, the upper coil and the lower coil have the same number of turns, which is 10 to 100.

[0014] As an embodiment, the segment lengths of the upper coil and the lower coil are the same, which is 6.4 mm to 80 mm.

[0015] As an embodiment, the flexible substrate is a flexible circuit board, and the flexible circuit board is fixed on the axle by bonding.

[0016] The present invention also provides an axle defect detection device, including a transmitting component and a receiving component, the transmitting component includes the axle defect detection waveguide transducer as described above, the flexible substrate in the waveguide transducer is fixed on the circumferential surface of one end of the axle, and the receiving component includes a receiver, and the receiver is fixed on the circumferential surface of the other end of the axle.

[0017] Compared with the prior art, the present invention has the following technical effects:

[0018] The axle defect detection waveguide transducer in the present invention is able to increase the intensity of the excited ultrasonic signal by more than twice compared to the traditional runway coil transducer by setting a double-layer obliquely folded coil and a permanent magnet located above the coil, thereby making the propagation distance of the sound wave longer and improving the defect detection sensitivity; and the waveguide transducer in the present invention can also reduce the width of the excited ultrasonic signal wave packet by half, making the equivalent length, width, and depth index parameters of the defect easier to quantify.

[0019] Other technical solutions in the present invention also have the following technical effects:

[0020] In the present invention, the current ratio in the upper coil and the lower coil is adjustable, and the emission angle of the spiral waveguide can be flexibly controlled to achieve effective monitoring of multi-directional crack defects in the axle, avoiding the situation where multi-directional crack defects are missed due to a single waveguide emission angle. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 This is a schematic diagram of the installation of a guided wave transducer for axle defect detection on an axle in one embodiment of the present invention;

[0023] Figure 2 This is a schematic structural diagram of a guided wave transducer for centralized axle defect detection according to an embodiment of the present invention;

[0024] Figure 3 This is a comparison chart of measurement results on an actual locomotive axle using a transducer having a traditional racetrack coil and a guided wave transducer in one embodiment of the present invention;

[0025] Figure 4A schematic diagram of measurement results of changing the current ratio between the upper coil and the lower coil in a waveguide transducer in one embodiment of the present invention to detect train axles with crack defects in different directions.

[0026] Description of reference numerals:

[0027] 1. Guided wave transducer; 2. Axle; 11. Permanent magnet; 12. Upper coil; 13. Lower coil. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] The purpose of the present invention is to provide an axle defect detection guided wave transducer and an axle defect detection device to solve the problems existing in the prior art. It can increase the intensity of the excited ultrasonic signal by more than two times compared with the traditional runway coil transducer, so that the propagation distance of the sound wave is longer and the defect detection sensitivity is improved; it can also reduce the width of the excited ultrasonic signal wave packet by half, so that the equivalent length, width and depth index parameters of the defect are easier to quantify.

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] Example 1:

[0032] like Figure 1 、 Figure 2As shown, this embodiment provides a waveguide transducer 1 for defect detection of an axle 2, comprising a flexible substrate, a permanent magnet 11, an upper coil 12, and a lower coil 13; wherein the flexible substrate has flexible and bendable properties, and serves as a carrier of the upper coil 12 and the lower coil 13, and is used to be fixed on the end circumferential wall surface of the axle 2. The permanent magnet 11 is located above the flexible substrate, and when in use, it is directly adsorbed on the axle 2 by magnetic force. A plurality of permanent magnets are arranged at intervals along the circumferential direction of the axle 2, and the magnetic poles of two adjacent permanent magnets 11 are opposite, and the distance between the two adjacent permanent magnets 11 is equal to the wavelength of the waveguide. The upper coil 12 is arranged on the upper surface of the flexible substrate, below the permanent magnet. Along the extension direction of the single permanent magnet 11, i.e., the length direction of the permanent magnet 11, the upper coil 12 forms an oblique zigzag shape, with the spacing between two adjacent turns of the conductor within the zigzag shape being equal to the wavelength of the waveguide. The lower coil 13 is disposed on the lower surface of the flexible substrate and forms an oblique zigzag shape along the extension direction of the single permanent magnet, with the spacing between two adjacent turns of the conductor within the zigzag shape being equal to the wavelength of the waveguide. In this embodiment, the oblique zigzag angle of the lower coil 13 complements the oblique zigzag angle of the upper coil 12. Specifically, after a symmetrical pattern of the upper coil 12 is formed with the central plane perpendicular to the upper surface of the flexible substrate as the symmetry plane, the oblique zigzag shape of the symmetrical pattern is identical to the oblique zigzag shape of the lower coil 13. In the direction perpendicular to the surface of the flexible substrate, the upper coil 12 and the lower coil 13 overlap to form an overlapping region. In the arrangement direction of the multiple permanent magnets 11, that is, in the width direction of the permanent magnets 11, the distribution range of the overlapping region is greater than the distribution range of the multiple permanent magnets. In the length direction of the permanent magnets 11, the direction of the current in the lower coil 13 is opposite to the direction of the current in the upper coil 12. It should be noted that the "opposite direction of the current in the lower coil 13 and the upper coil 12" mentioned here does not mean that the direction of the current at a certain position in the upper coil 12 is opposite to the direction of the current at a certain position in the lower coil 13. Rather, it means that in the length direction of the permanent magnet 11, the flow trend of the current in the upper coil 12 is opposite to the flow trend of the current in the lower coil 13. For example, the flow trend of the current in the upper coil 12 is from a position close to the first end of the permanent magnet 11 to a position close to the second end, but in a certain turn of the wire, the actual flow direction of the current may be opposite to the flow trend; while the flow trend of the current in the lower coil 13 is from a position close to the second end of the permanent magnet 11 to a position close to the first end.

[0033] When in use, both the upper coil 12 and the lower coil 13 are connected to a pulse power generator.

[0034] Therefore, the axle 2 defect detection waveguide transducer 1 in this embodiment can increase the intensity of the excited ultrasonic signal by more than twice compared with the traditional runway coil transducer by setting a double-layer obliquely folded coil and a permanent magnet 11 located above the coil, so that the propagation distance of the sound wave is longer and the defect detection sensitivity is improved; and the waveguide transducer 1 in this embodiment can also reduce the width of the excited ultrasonic signal wave packet by half, making the equivalent length, width, and depth index parameters of the defect easier to quantify.

[0035] As an implementation method, in this embodiment, the ratio of the current in the upper coil 12 to the current in the lower coil 13 is adjustable, and the emission angle of the spiral waveguide can be flexibly controlled to achieve effective monitoring of multi-directional crack defects in the axle 2, avoiding the situation where multi-directional crack defects are missed due to a single waveguide emission angle.

[0036] As an implementation manner, in this embodiment, the bending angle of the upper coil 12 relative to the extension direction of the single permanent magnet 11 is 45°, and the bending angle of the lower coil 13 relative to the extension direction of the single permanent magnet 11 is 135°.

[0037] As one embodiment, the distance between two adjacent permanent magnets 11 is 16 mm.

[0038] As one embodiment, the width of a single permanent magnet is 4 mm to 6 mm, and 5 mm may be selected.

[0039] As an embodiment, the radial cross-sectional area of ​​the conductors of the upper coil 12 and the lower coil 13 is the same, which is 0.2 mm. 2 ~0.5mm 2 .

[0040] According to one embodiment, the upper coil 12 and the lower coil 13 have the same number of turns, which is 10 to 100.

[0041] As one embodiment, the segment lengths of the upper coil 12 and the lower coil 13 are the same, and are 6.4 mm to 80 mm.

[0042] As one implementation method, the flexible substrate in this embodiment is a flexible circuit board, the upper coil 12 and the lower coil 13 are fixed on the flexible circuit board by engraving, and the flexible circuit board is fixed on the axle 2 by bonding; and the permanent magnet 11 is adsorbed and fixed based on the suction force between itself and the axle 2, and is located above the flexible circuit board.

[0043] Example 2:

[0044] The present invention provides an axle 2 defect detection device, comprising a transmitting assembly and a receiving assembly. The transmitting assembly includes the axle 2 defect detection guided wave transducer 1 described in Example 1. During use, the axle 2 is placed horizontally, the flexible substrate in the guided wave transducer 1 is fixed to the circumferential surface of one end of the axle 2, and the receiving assembly includes a receiver fixed to the circumferential surface of the other end of the axle 2. The receiver can adopt the structure of existing devices and is not limited in this embodiment.

[0045] Example: The length, end diameter, shaft diameter, and journal diameter of the axle 2 are 2407mm, 105mm, 192mm, and 130mm, respectively; the spacing between the permanent magnets 11 is fixed at 16mm; the double-layer staggered oblique folded coil and the receiving end coil below the rectangular periodic permanent magnet 11 are both printed on the FPC to achieve a tight fit with the cylindrical axle 2; as mentioned above, the lift-off value of the transducer is 1mm. The measurement diagram of this embodiment on the axle is compared with the measurement diagram of a traditional transducer with a runway coil. Figure 3 The measurement diagram after changing the current ratio between the upper coil 12 and the lower coil 13 is shown in FIG. Figure 4 shown.

[0046] Adaptive changes based on actual needs are all within the scope of protection of the present invention.

[0047] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A guided wave transducer for detecting axle defects, characterized in that: include: A flexible substrate, the flexible substrate being fixed to the circumferential wall surface of the end portion of the axle; A permanent magnet, wherein the permanent magnet is located above the flexible substrate and is arranged in a plurality of intervals, with the magnetic poles of two adjacent permanent magnets being opposite to each other; and the distance between two adjacent permanent magnets being equal to the wavelength of the guided wave; an upper coil, the upper coil being disposed on top of the flexible substrate and below the permanent magnet, wherein the upper coil is in an oblique folded shape along the extension direction of a single permanent magnet, and wherein the spacing between the conductors in the oblique folded shape of the upper coil is equal to the wavelength of the guided wave; and a lower coil, the lower coil being disposed at the bottom of the flexible substrate and being in an obliquely folded shape along the extension direction of a single permanent magnet, wherein the spacing of the conductors in the obliquely folded shape of the lower coil is equal to the wavelength of the waveguide, and the oblique folding angle of the lower coil is complementary to the oblique folding angle of the upper coil; in a direction perpendicular to the surface of the flexible substrate, the upper coil and the lower coil overlap to form an overlapping region, and in the arrangement direction of the plurality of permanent magnets, the distribution range of the overlapping region is greater than the distribution range of the plurality of permanent magnets; In the extending direction of the single permanent magnet, the direction of the current in the lower coil is opposite to the direction of the current in the upper coil.

2. The guided wave transducer for detecting axle defects according to claim 1, characterized in that: The bending angle of the upper coil relative to the extension direction of the single permanent magnet is 45°, and the bending angle of the lower coil relative to the extension direction of the single permanent magnet is 135°.

3. The guided wave transducer for detecting axle defects according to claim 1, characterized in that: The ratio of the current in the upper coil to the current in the lower coil is adjustable.

4. The guided wave transducer for detecting axle defects according to claim 1, characterized in that: The distance between two adjacent permanent magnets is 16 mm.

5. The guided wave transducer for detecting axle defects according to claim 1, characterized in that: The width of a single permanent magnet is 4 mm to 6 mm.

6. The guided wave transducer for detecting axle defects according to claim 1, characterized in that: The radial cross-sectional area of ​​the conductors of the upper coil and the lower coil is the same, which is 0.2 mm 2 ~0.5mm 2 .

7. The guided wave transducer for detecting axle defects according to claim 1, characterized in that: The upper coil and the lower coil have the same number of turns, which is 10 to 100.

8. The guided wave transducer for detecting axle defects according to claim 1, characterized in that: The segment lengths of the upper coil and the lower coil are the same, ranging from 6.4 mm to 80 mm.

9. The guided wave transducer for detecting axle defects according to claim 1, characterized in that: The flexible substrate is a flexible circuit board, and the flexible circuit board is fixed on the axle by bonding.

10. An axle defect detection device, characterized in that: It includes a transmitting component and a receiving component, the transmitting component includes the axle defect detection waveguide transducer according to any one of claims 1 to 9, the flexible substrate in the waveguide transducer is fixed on the circumferential surface of one end of the axle, and the receiving component includes a receiver, and the receiver is fixed on the circumferential surface of the other end of the axle.

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