Axle defect detection guided wave transducer and axle defect detection device

Abstract

The invention provides an axle defect detection guided wave transducer and an axle defect detection device, and relates to the technical field of axle defect detection.The axle defect detection guided wave transducer comprises a flexible base material, a permanent magnet, an upper layer coil and a lower layer coil; the flexible base material is used for being fixed to the circumferential wall face of the end of an axle. The permanent magnets are located above the flexible base material, and the magnetic poles of every two adjacent permanent magnets are opposite. The distance between every two adjacent permanent magnets is equal to the wavelength of guided waves. The upper-layer coil and the lower-layer coil are arranged at the top and the bottom of the flexible base material respectively and are both in an inclined inflection shape, and the inclined inflection angle of the lower-layer coil and the inclined inflection angle of the upper-layer coil are complementary; the current direction in the lower-layer coil is opposite to that in the upper-layer coil; the intensity of an excited ultrasonic signal can be improved by more than two times, so that the propagation distance of sound waves is longer; in addition, the guided wave transducer can reduce the width of an excited ultrasonic signal wave packet by half, so that defect parameters are more easily quantized.

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] As an important carrier for the transportation of passengers and bulk goods, high-speed trains are the concentrated embodiment of high-tech achievements in rail transit. However, high-speed trains often run under harsh conditions such as strong vibration, heavy load, and high cycle. The running mechanism directly involved in the train drive faces extreme environments such as sandstorms, heavy rain, high temperature, and high cold all year round, and the service conditions are very complex. Among them, the axle is a key load-bearing component of the bogie of a high-speed train. It is directly connected to the wheels and suspension devices. It not only bears the direct output of the gear transmission system, but also bears the weight and additional load of the locomotive as the core component of the wheelset. However, the axle journal is subjected to rotational bending and impact for a long time during service, and fatigue cracks are very likely to occur. When the crack develops to a certain extent, the journal is prone to cold shearing under the action of alternating stress, which leads to major safety accidents such as train derailment. Therefore, how to carry out high-sensitivity online detection and quantitative safety assessment of microcracks on rotating axles of in-service trains is a key issue that needs to be solved in the field of high-speed train safety detection.

[0003] The inventors are aware of a detection technology that uses a contact piezoelectric ultrasonic transducer to rotate synchronously with a hollow axle to excite ultrasonic guided waves, and obtains the circumferential and axial sound field signals of the axle surface defects through the full circumferential arrangement and excitation of the transducer, and discusses the sensitivity of guided waves to the depth and length of defects. However, the operating environment of high-speed trains is very harsh, and the axles are in a state of high-speed rotation and reciprocating vibration for a long time. The existing acoustic emission detection technology is heavily dependent on complex denoising algorithms and crack signal feature extraction methods, and is only sensitive to large cracks in the expansion process, and cannot achieve effective detection of 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. The intensity of the excited ultrasonic signal can be increased 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; the width of the excited ultrasonic signal wave packet can be reduced 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 axle defects, comprising 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, and the magnetic poles of two adjacent permanent magnets are opposite; the distance 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, located 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 distance between the wires 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, along the extension direction of a single permanent magnet, the lower coil is in an oblique folded shape, the spacing of the wires 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 vertical direction of the surface of the flexible substrate, the upper coil and the lower coil overlap to form an overlapping area, in the arrangement direction of the plurality of permanent magnets, the distribution range of the overlapping area is greater than the distribution range of the plurality of permanent magnets; in the extension direction of a single permanent magnet, the current direction in the lower coil is opposite to the current direction in the upper coil.

[0008] As an implementation manner, 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 implementation manner, the ratio of the current in the upper coil to the current in the lower coil is adjustable.

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

[0011] As 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 conductor of the upper coil and the lower coil is the same, which is 0.2 mm 2 ~0.5mm 2 .

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

[0014] As an implementation manner, 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 implementation manner, 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, comprising a transmitting component and a receiving component, wherein the transmitting component comprises the axle defect detection waveguide transducer as described above, wherein the flexible substrate in the waveguide transducer is fixed on the circumferential surface of one end of the axle, and the receiving component comprises a receiver, wherein 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 can increase the intensity of the excited ultrasonic signal by more than two times compared with the traditional runway coil transducer by setting a double-layer oblique folded coil and a permanent magnet 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 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 size 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 drawings required for use in the embodiments will be briefly introduced below. 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 creative labor.

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

[0023] Figure 2 A schematic diagram of the structure of a guided wave transducer for concentrated axle defect detection according to an embodiment of the present invention;

[0024] Figure 3 A comparison chart of measurement results of using a transducer with a conventional racetrack coil and a waveguide transducer in one embodiment of the present invention on an actual locomotive axle;

[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 be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work 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. The intensity of the excited ultrasonic signal can be increased 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; the width of the excited ultrasonic signal wave packet can be reduced 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] Embodiment 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 in an interval arrangement along the circumferential direction of the axle 2, and the magnetic poles of two adjacent permanent magnets 11 are opposite, and the distance between 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, and is located below the permanent magnet. Along the extension direction of the single permanent magnet 11, that is, the length direction of the permanent magnet 11, the upper coil 12 is in an oblique folded shape, and the spacing between two adjacent turns of the wire in the oblique folded shape is equal to the wavelength of the waveguide; the lower coil 13 is arranged on the lower surface of the flexible substrate, and along the extension direction of the single permanent magnet, the lower coil 13 is in an oblique folded shape, and the spacing between two adjacent turns of the wire in the oblique folded shape is equal to the wavelength of the waveguide. In this embodiment, the oblique folding angle of the lower coil 13 is complementary to the oblique folding angle of the upper coil 12, that is, the central plane perpendicular to the upper surface of the flexible substrate is used as the symmetry plane, and after the symmetric figure of the upper coil 12 is made, the oblique folding shape of the symmetric figure is the same as the oblique folding shape of the lower coil 13. In the vertical direction of the surface of the flexible substrate, the upper coil 12 and the lower coil 13 overlap to form an overlapping area. 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 area is greater than the distribution range of the multiple permanent magnets. In the length direction of the permanent magnet 11, the current direction in the lower coil 13 is opposite to the current direction in the upper coil 12. It should be noted that the opposite current direction in the lower coil 13 and the upper coil 12 mentioned here does not mean that the current direction at a certain position in the upper coil 12 is opposite to the current direction at a certain position in the lower coil 13, but 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 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 two times compared with the traditional runway coil transducer by setting a double-layer oblique folded coil and a permanent magnet 11 located above the coil, thereby making the propagation distance of the sound wave longer and improving the defect detection sensitivity; 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 mode, 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, thereby avoiding the omission of multi-directional crack defects 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 one 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] As 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, which is 6.4 mm to 80 mm.

[0042] As one implementation mode, 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] Embodiment 2:

[0044] The present invention provides an axle 2 defect detection device, comprising a transmitting component and a receiving component, wherein the transmitting component comprises the axle 2 defect detection waveguide transducer 1 as described in Example 1. When in use, the axle 2 is placed horizontally, the flexible substrate in the waveguide transducer 1 is fixed on the circumferential surface of one end of the axle 2, and the receiving component comprises a receiver, which is fixed on the circumferential surface of the other end of the axle 2. The receiver can adopt the structure of an existing device, and this embodiment does not limit the structure of the receiver.

[0045] Example: The length, end diameter, shaft diameter, and journal diameter of the axle 2 are 2407mm, 105mm, 192mm, and 130mm, respectively; the spacing of the permanent magnets 11 is fixed at 16mm; the double-layer staggered oblique folded coil and the receiving end coil under the rectangular periodic permanent magnet 11 are printed on the FPC to achieve a close fit with the cylindrical axle 2; according to the 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 the 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 made according to actual needs are all within the protection scope 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 used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood 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 is used to be fixed on the circumferential wall surface of the end of the axle; A permanent magnet, wherein the permanent magnet is located above the flexible substrate and is arranged in a plurality of intervals, and the magnetic poles of two adjacent permanent magnets are opposite; and the interval between two adjacent permanent magnets is equal to the wavelength of the waveguide; An upper coil, the upper coil is arranged on the top of the flexible substrate and below the permanent magnet. Along the extension direction of the single permanent magnet, the upper coil is in an oblique folded shape, and the spacing of the wires 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 arranged at the bottom of the flexible substrate, and being in an oblique folded shape along the extension direction of a single permanent magnet, wherein the spacing of the wires 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 vertical direction of 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 plurality of permanent magnets, the distribution range of the overlapping area 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 axle defect detection 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 axle defect detection 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 number of turns of the upper coil and the lower coil is the same, which is 10-100.

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 comprises a transmitting component and a receiving component, wherein the transmitting component comprises the axle defect detection waveguide transducer as claimed in any one of claims 1 to 9, wherein the flexible substrate in the waveguide transducer is fixed on the circumferential surface of one end of the axle, and the receiving component comprises a receiver, wherein the receiver is fixed on the circumferential surface of the other end of the axle.

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