A micro electromagnetic eddy current sensor device and a detection method thereof

Abstract

The application discloses a micro electromagnetic eddy current sensor device and a detection method thereof, and relates to a nondestructive testing technology for crack defects (12) of air holes (11) of an aircraft engine turbine blade (1). The device is connected to a detector (2) through a lead (21), and the sensor device (3) comprises a controller (31) and a detection coil (32). The detection coil (32) is characterized by being an array coil unit (321) vertically arranged in a winding direction. The volume of the detection coil unit does not need to be too small, and the manufacturing difficulty of the detection probe in the detection device is greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of nondestructive testing technology, specifically to the fabrication process of eddy current testing sensors, and particularly to a micro electromagnetic eddy current sensor device and its testing method. Background Technology

[0002] As is well known, the aero-engine is the core of the entire aircraft, and its performance directly determines the overall performance of the aircraft. Among aero-gas turbine engines, the turbine blades operate in the harshest environment and experience the most complex stresses. At the same time, turbine blades are also key to achieving high performance in aero-engines while maintaining small size and light weight. Therefore, turbine blades are the "core of the core" of the entire aircraft. The requirements of aero-gas turbine engines also necessitate extremely high operating and load temperatures for turbine blades. Cooling technology for turbine blades is also of great importance. By designing cooling channels and cooling holes on the blades, "cryogenic gas" from the compressor is drawn into the interior of the turbine blades and then ejected from the cooling holes on the blade surface, forming a gas film that isolates the relatively low-temperature turbine blades from the high-temperature combustion gases in its operating environment—this is known as film cooling technology.

[0003] As attached Figure 1 In the hollow turbine blade (1), the pores (11) are extremely small, usually about 1 μm in diameter, and their shape and direction are also special and different. The cracks (12) around the pores (11) are also extremely small, making non-destructive testing quite difficult. Eddy current testing probes need to be made extremely small, and the fabrication process of tiny detection coils is very difficult, and the assembly is also very challenging.

[0004] To address the above-mentioned shortcomings, the present invention adopts the following technical solution. Summary of the Invention

[0005] The purpose of this invention is to provide a micro-electromagnetic eddy current sensor device and its detection method. The disclosed technical solution is as follows:

[0006] A micro electromagnetic eddy current sensor device is used for non-destructive testing of crack defects (12) in ventilation holes (11) of turbine blades (1) of aircraft engines, etc. It is connected to a testing instrument (2) via a lead wire (21). The sensor device (3) includes a controller (31) and a detection coil (32). The detection coil (32) is characterized in that it is an array coil unit (321) with several winding directions arranged vertically. The coil unit (321) is configured as a spiral wound coil with at least one turn, and the spiral coil winding height L is less than the coil radial height D1.

[0007] Furthermore, the coil unit (321) is configured as multiple identical helical coils arranged vertically side by side on the same horizontal straight line AA, with the helical coils being any of the following types: cylindrical helical coil, planar helical coil, and tower-shaped helical coil. Under normal circumstances, the total thickness N of the multiple coil units (321) arranged side by side is less than the radial width D2 of the coil. When scanning for detection, depending on the on-site detection requirements, the transverse direction of the coil winding axis is selected as the scanning detection direction for ultra-small diameter hole detection, while the axial direction of the coil winding axis is selected as the scanning detection direction for larger range detection.

[0008] In another configuration, the coil unit (321) is configured as multiple identical helical coils arranged vertically side-by-side on horizontal straight lines AA and BB at different heights around the central axis. The helical coils can be any of the following: cylindrical helical coils, planar helical coils, or tower-shaped helical coils. When the coil units (321) are set at different heights, the sensor device with the pointed and convex shape of the coil units (321) is configured as a pen tip structure. During scanning, appropriate tilting ensures that the lift-off value of the coil and the detection surface of the object being inspected is equal, which also facilitates better line-of-sight during scanning.

[0009] Furthermore, the multiple coil units (321) of the detection coil are configured as multiple coils with the same winding direction. Each coil node lead (3211) can output a signal individually or be connected in series to be used as a detection coil. Alternatively, the multiple coil units (321) can be configured as two types of coils with different winding directions arranged symmetrically. Each coil node lead (3211) can output a signal individually, and those on the same half can be connected in series to be used as a detection coil.

[0010] Furthermore, the total thickness N of the array arrangement of multiple coil units (321) is less than the radial width D2 of the coil, and the sensor device is made into a flat shape according to the shape of the combination of several coil units (321). During scanning detection, depending on the on-site detection requirements, the transverse direction of the coil winding shaft is selected as the scanning detection direction for ultra-small diameter hole detection, and the axial direction of the coil winding shaft is selected as the scanning detection direction for larger range detection.

[0011] In addition, the sensor device (3) also includes a first excitation coil (33) wound around the periphery of the detection coil (32). Alternatively, the sensor device (3) also includes a plurality of second excitation coils (34) disposed above the detection coil (32). The first excitation coil (33) and the second excitation coil (34) can be provided according to actual needs, or both types of detection coils can be provided simultaneously, and the number of excitation coils of the same type can also be arbitrarily selected and designed.

[0012] This invention also discloses a detection method for a micro electromagnetic eddy current sensor device, the specific steps of which are as follows:

[0013] a. Selection of scanning direction of the detection device: According to the needs of the site, when detecting ultra-small diameter holes, the transverse direction of the coil winding shaft is selected as the scanning detection direction, and when detecting a larger range, the axial direction of the coil winding shaft is selected as the scanning detection direction;

[0014] b. Detection coil selection: Select the on / off state of the detection coil unit, and select whether the individual coil units are connected in series or in parallel;

[0015] c. Detection data collection: Collect the detection signal data of each detection coil unit or series coil unit combination, and return to step a to scan repeatedly multiple times;

[0016] d. Combined data analysis: The detection signal data from repeated scanning can be comprehensively analyzed and processed to form a holographic image analysis.

[0017] The scanning direction and coil units can be repeatedly selected in the same or different numbers and connection methods, and the same or different scanning tests can be performed according to the detection requirements such as on-site data imaging.

[0018] In step b, the selection of the detection coil and its connection method involves using an encoder switch for selection and switching, and also includes extracting the strength characteristics of each coil signal to filter the detection data of the detection coil unit.

[0019] Based on the above technical solution, the present invention has the following beneficial effects:

[0020] 1. The detection coil of the present invention is arranged vertically, which greatly reduces the width of the detection device in the scanning direction, while realizing that the volume of the detection coil unit does not need to be too small, which greatly reduces the manufacturing difficulty of the detection probe in the detection device.

[0021] Second, the detection coil of the detection device of the present invention is composed of multiple vertical coil units. By selecting the coil units and their series connection method through coding software, the effect of adjusting and selecting a small detection range can be achieved more flexibly.

[0022] Third, the detection device of the present invention is based on the fact that the thickness of the combined array arrangement of coil units is less than the radial width of a single coil unit, and the winding length of a single coil unit is much smaller than the radial width of the coil unit. A more optimized choice is a planar spiral, that is, a single detection coil unit is very small. Moreover, by selecting the scanning detection direction, the detection coil can be set to scan laterally on the winding axis of a single coil unit. That is, the detection area in the scanning direction is the wire diameter of the detection coil, thus achieving a very small single detection scanning surface.

[0023] Fourth, in the overall setup of the detection device, the detection probe is set into a flat shape according to the arrangement and thickness of the coil unit. During scanning and detection, the shape is similar to a paintbrush and can be selected in the horizontal and vertical directions, making it easier to align with extremely small and complex detection surfaces such as the ultra-small diameter holes of turbine blades in aero-engines. Attached Figure Description

[0024] Figure 1 This is a schematic diagram illustrating an application scenario of the preferred embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of a preferred embodiment of the present invention;

[0026] Figure 3 This is a schematic diagram of an enlarged detection coil according to a preferred embodiment of the present invention;

[0027] Figure 4 This is a schematic diagram of the planar spiral detection device according to the preferred embodiment of the present invention;

[0028] Figure 5 A magnified schematic diagram of the planar spiral circular detection coil according to the preferred embodiment of the present invention;

[0029] Figure 6 A magnified schematic diagram of the planar spiral square detection coil according to the preferred embodiment of the present invention;

[0030] Figure 7 This is a schematic diagram of another planar spiral detection device according to the preferred embodiment of the present invention;

[0031] Figure 8 An enlarged schematic diagram of two detection coils with a planar spiral elliptical shape, representing a preferred embodiment of the present invention;

[0032] Figure 9 A magnified schematic diagram of the tower-shaped spiral detection coil according to the preferred embodiment of the present invention;

[0033] Figure 10 A schematic diagram of a detection device with a detection coil unit at different horizontal heights, representing a preferred embodiment of the present invention;

[0034] Figure 11 This is a magnified schematic diagram of the detection coil unit at different horizontal heights, representing the preferred embodiment of the present invention.

[0035] Figure 12 A magnified schematic diagram of the planar spiral detection coil unit at different horizontal heights, representing the preferred embodiment of the present invention;

[0036] Figure 13 A schematic diagram of a detection device for a tower-shaped detection coil unit at different horizontal heights, representing the preferred embodiment of the present invention;

[0037] Figure 14 A magnified schematic diagram of the tower-shaped detection coil unit at different horizontal heights, representing the preferred embodiment of the present invention;

[0038] Figure 15 This is a schematic diagram of the method flow of the preferred embodiment of the present invention. Detailed Implementation

[0039] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0040] like Figure 1 ,to Figure 13 As shown, a micro electromagnetic eddy current sensor device is used for non-destructive testing of crack defects 12 in ventilation holes 11 of turbine blades 1 of aircraft engines, etc. It is connected to a testing instrument 2 via a lead wire 21. The sensor device 3 includes a controller 31 and a detection coil 32. The detection coil 32 is characterized by being an array coil unit 321 with several winding directions arranged vertically. The coil unit 321 is configured as a spiral wound coil with at least one turn, and the spiral coil winding height L is less than the coil radial height D1.

[0041] Furthermore, the coil unit 321 is configured as multiple identical helical coils arranged vertically side by side on the same horizontal straight line AA, with the helical coils being any of the following types: cylindrical helical coils, planar helical coils, and tower-shaped helical coils. For example... Figure 3 The cylindrical helical coil unit structure in the middle, Figures 4 to 8 These are schematic structures of circular, square, and elliptical planar helical coils, respectively. Figure 9 The tower shape in the middle. Under normal circumstances, such as Figure 3 As shown, the total thickness N of the multiple coil units 321 arranged side by side is less than the radial width D2 of the coil. When scanning and detecting, depending on the on-site detection requirements, the transverse direction of the coil winding shaft is selected as the scanning and detection direction when detecting ultra-small diameter holes, and the axial direction of the coil winding shaft is selected as the scanning and detection direction when detecting larger ranges.

[0042] In another configuration, the coil unit 321 is configured as multiple identical helical coils arranged vertically side-by-side on horizontal straight lines AA and BB at different heights around the central axis. The helical coils can be any of the following types: cylindrical helical coils, planar helical coils, or tower-shaped helical coils. For example... Figure 10 and Figure 12 The schematic diagram of the detection device shows that when the coil unit 321 is set at different heights, the sensor device with the pointed shape of the coil unit 321 is set as a pen tip structure. During scanning, appropriate tilting makes the lift-off value of the coil equal to that of the detection surface of the workpiece, and also facilitates the line of sight during scanning. Figure 10 and Figure 11 A schematic diagram of a symmetrical detection unit with a cylindrical helical coil at different horizontal heights, and Figure 13 and Figure 14 Schematic diagram of the tower-shaped spiral structure at different horizontal heights.

[0043] Furthermore, the multiple coil units 321 of the detection coil are configured as multiple coils with the same winding direction. Each coil node lead 3211 can be connected to a signal individually or connected in series to be used as a detection coil. Alternatively, the multiple coil units 321 are configured as two types of coils with different winding directions arranged symmetrically. Each coil node lead 3211 can be connected to a signal individually, and those on the same half can be connected in series to be used as a detection coil.

[0044] Furthermore, the total thickness N of the array of multiple coil units 321 is less than the radial width D2 of the coil, and the sensor device is made into a flat shape according to the shape of the combination of several coil units 321. During scanning detection, depending on the on-site detection requirements, the transverse direction of the coil winding shaft is selected as the scanning detection direction for ultra-small diameter hole detection, and the axial direction of the coil winding shaft is selected as the scanning detection direction for larger range detection.

[0045] In addition, such as Figure 2 As shown, the sensor device 3 further includes a first excitation coil 33 wound around the periphery of the detection coil 32. Alternatively, the sensor device 3 may also include a plurality of second excitation coils 34 disposed above the detection coil 32. The first excitation coil 33 and the second excitation coil 34 may be provided according to actual needs, or both types of detection coils may be present simultaneously, and the number of excitation coils of the same type may be arbitrarily selected and designed.

[0046] like Figure 15 As shown, the present invention also discloses a detection method for a micro electromagnetic eddy current sensor device, the specific steps of which are as follows:

[0047] a. Selection of scanning direction of the detection device: According to the needs of the site, when detecting ultra-small diameter holes, the transverse direction of the coil winding shaft is selected as the scanning detection direction, and when detecting a larger range, the axial direction of the coil winding shaft is selected as the scanning detection direction;

[0048] b. Detection coil selection: Select the on / off state of the detection coil unit, and select whether the individual coil units are connected in series or in parallel;

[0049] c. Detection data collection: Collect the detection signal data of each detection coil unit or series coil unit combination, and return to step a to scan repeatedly multiple times;

[0050] d. Combined data analysis: The detection signal data from repeated scanning can be comprehensively analyzed and processed to form a holographic image analysis.

[0051] The scanning direction and coil units can be repeatedly selected in the same or different numbers and connection methods, and the same or different scanning tests can be performed according to the detection requirements such as on-site data imaging.

[0052] In step b, the selection of the detection coil and its connection method involves using an encoder switch for selection and switching, and also includes extracting the strength characteristics of each coil signal to filter the detection data of the detection coil unit.

[0053] The above is one embodiment of the present invention. Furthermore, it should be noted that any equivalent or simple variations made to the structure, features, and principles described in this patent concept are included within the scope of protection of this patent.

Claims

1. A micro-electromagnetic eddy current sensor device for detecting crack defects in the ventilation holes of eddy current blades of aircraft engines, connected to a detection instrument via leads, the sensor device comprising a controller (31) and a detection coil (32), characterized in that... The detection coil (32) is an array coil unit (321) with several winding direction surfaces arranged vertically; The coil unit (321) is configured as a spiral wound coil with at least one turn, and the spiral coil winding height L is less than the coil radial height D1. The coil unit (321) is configured as multiple identical spiral coils arranged in parallel and vertically on the same horizontal straight line AA, or the coil unit (321) is configured as multiple identical spiral coils arranged in parallel and vertically on horizontal straight lines AA and BB at different heights, with the central axis wound around it. The total thickness N of the array arrangement of multiple coil units (321) is less than the radial width D2 of the coil, and the sensor device is made into a flat shape according to the shape of the combination of several coil units (321).

2. The micro-electromagnetic eddy current sensor device according to claim 1, characterized in that... The spiral coil is any one of multiple coil units (321) of cylindrical spiral coil, planar spiral coil, or tower-shaped spiral coil.

3. The micro electromagnetic eddy current sensor device according to claim 1, characterized in that... The multiple coil units (321) are configured as multiple coils with the same winding direction. Each coil node lead (3211) is connected to a signal individually, or they are connected in series together as a detection coil.

4. The micro electromagnetic eddy current sensor device according to claim 1, characterized in that... The multiple coil units (321) are configured as two types of coils with different winding directions symmetrically arranged. Each coil node lead (3211) is connected to a signal separately, or the same half of the coil is connected together in series to be used as a detection coil.

5. A micro electromagnetic eddy current sensor device according to claim 1, characterized in that... The sensor device (3) further includes a first excitation coil (33) wound around the periphery of the detection coil (32).

6. The micro-electromagnetic eddy current sensor device according to claim 1, characterized in that... The sensor device (3) further includes a plurality of second excitation coils (34) disposed above the detection coil (32).

7. A detection method for a micro electromagnetic eddy current sensor device, characterized in that... The specific steps for using a micro electromagnetic eddy current sensor device according to any one of claims 1 to 6 are as follows: a. Selection of scanning direction of detection device: According to the needs of the site, when detecting ultra-small diameter holes, the transverse direction of the coil winding shaft is selected as the scanning detection direction, and when detecting a larger range, the axial direction of the coil winding shaft is selected as the scanning detection direction; b. Detection coil selection: Select the on / off state of the detection coil unit, and select whether the individual coil units are connected in series or in parallel; c. Detection data collection: Collect the detection signal data of each detection coil unit or series coil unit combination, and return to step a to scan repeatedly multiple times; d. Combined data analysis: The detection signal data from repeated scanning can be comprehensively analyzed and processed to combine them into a holographic image analysis.

8. The detection method of the micro electromagnetic eddy current sensor device according to claim 7, characterized in that... In step b, the selection of the detection coil and its connection method involves using an encoder switch for selection and switching, and also includes extracting the strength characteristics of each coil signal to filter the detection data of the detection coil unit.

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