A method and a detection device for improving the performance of eddy current testing of flexible PCBs

Abstract

The application discloses a method and a detection device for improving the performance of eddy current detection of a flexible PCB, which are used for the eddy current detection of metal devices with irregular arc curved surfaces, such as mortise and tenon joints in a rotor blade mounting device of an aero-engine, and the like. The technical method comprises the following steps: a flexible bag with a deformable sandbag type is used to press a flexible PCB detection probe provided with an array type eddy current detection sensor to be closely attached to an irregular detection surface, and then corresponding detection signal data are extracted. The detection device comprises a multi-channel eddy current detection instrument (3), a flexible bag (21) and a flexible PCB detection probe (22). The flexible PCB detection probe (22) is arranged on the side of the flexible bag (21) close to a detected object, and an array type eddy current detection sensor (221) is arranged on the flexible PCB detection probe (22), so as to form an ultrathin film type detection probe. The effective penetration depth of the eddy current is improved, and meanwhile, the effective attachment between the flexible sensor and the workpiece can be better ensured, so that the expected detection effect of improving the detection performance is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of non-destructive testing, in particular to eddy current testing of blades such as those of an aero turbine engine, and more particularly to a method and device for improving the performance of flexible PCB eddy current testing. BACKGROUND

[0002] With the development of science and technology, various arrayed eddy current sensors suitable for medium and large scale metal workpieces have emerged, in particular, various linear array or planar array eddy current sensors of various driving forms composed of flexible PCB multilayer boards are increasingly applied in the field of non-destructive testing such as aerospace. This is because, as shown in FIG. 1, compared with conventional arrayed eddy current sensors composed of magnetic cores and coils, the flexible PCB type detection probe 22 is provided with arrayed detection sensors 221 and an electrical connection adapter 222. The flexible PCB multilayer board not only has good consistency, but also is suitable for various applications of detection surfaces with varying curvatures, such as metal workpieces with irregular surfaces such as aircraft blades, and the manufacturing efficiency of the arrayed probe of the flexible circuit board type is greatly improved. However, due to the current multi-coil process of the flexible PCB, it is difficult to implant a ferrite core, so its use frequency is higher, especially for occasions with higher detection accuracy requirements or workpieces with deeper eddy current penetration depth. The flexible PCB board can only increase the number of layers to increase the number of turns of the coil, but in this way, its flexibility is limited and cannot complete special detection tasks. Figure 3 To solve the above problems, the present application adopts the following technical solutions for further improvement.

[0003] SUMMARY The present application provides a method and device for improving the performance of flexible PCB eddy current testing, and the technical solutions disclosed are as follows:

[0004] The present application provides a method and device for improving the performance of flexible PCB eddy current testing, and the technical solutions disclosed are as follows:

[0005] A method for improving the performance of flexible PCB eddy current testing, for example, the mortise and tenon joint of a rotor blade mounting device, metal devices with irregular arc-shaped curved detection surfaces, and eddy current testing, characterized by a flexible bag with a deformable sandbag type that presses the flexible PCB detection probe provided with arrayed eddy current detection sensors against the irregular detection surface, and a technical method for extracting the corresponding detection signal data, the specific steps are as follows:

[0006] a. Place the detection device: prepare a flexible bag of appropriate size and width and a flexible PCB detection probe combination, the arrayed eddy current detection sensors provided on the PCB detection probe are detected by a multi-channel arrayed eddy current detector operating each eddy current sensor, and the eddy current detector acquires the detection signal data of each eddy current detection sensor;

[0007] b. Selecting the detection sensor: through the flexible PCB board deformation to fit the irregular detection surface, selecting the actual detection eddy current detection sensor;

[0008] c. Actual detection: applying the corresponding frequency excitation power to the arrayed eddy current detection sensor on the flexible PCB board, performing eddy current nondestructive testing on the detected object, and extracting the corresponding detection signal data;

[0009] d. Detection data analysis: analyzing the extracted corresponding detection signal data and evaluating the defect parameters of the detected object.

[0010] Further, the inside of the flexible bag is a ferrite powder. The sandbag type flexible bag formed by the ferrite powder can effectively attach the flexible PCB board type probe to the detected curved surface, and the ferrite as a good conductor of magnetism has the effect of enhancing the detection performance and can improve the effective penetration depth of the eddy current detection signal, accordingly, the detection frequency of the flexible PCB arrayed eddy current sensor can be greatly reduced, and the detection performance can be improved.

[0011] Further, in the step b of selecting the detection sensor, the distance between each sensor in the arrayed sensor provided on the flexible PCB board eddy current detection probe and the center position of the flexible bag is compared before and after the fitting, to select the actual detection sensor.

[0012] Further, the interval value between the sensor device provided on the flexible bag and each sensor on the flexible PCB board is compared before and after the fitting detection, and the sensor in the arrayed sensor used for actual eddy current detection is selected after evaluation and analysis. The sensor device provided on the flexible bag is set as a capacitive detection sensor, and the preferred implementation is to analyze and calculate the interval between the sensor device and the eddy current detection sensor through the capacitance change between the capacitive electrode sheet or planar spiral coil and the eddy current sensor coil.

[0013] Further, the multi-channel eddy current detection instrument selects the eddy current detection sensor with an interval value greater than that when not fitted as the real-time detection sensor. In many cases, the inner concave irregular detection surface of the metal device needs to be detected, such as the blade mounting tenon groove of the aviation turbine engine. The defects of the groove part are more difficult to be found and more difficult to be detected by the appropriate probe.

[0014] The application also discloses a flexible PCB eddy current detection device for eddy current detection of metal devices with irregular arc curved surfaces, such as mortise (11) in a rotor blade (1) mounting device of an aero-engine, etc., which is connected to a multi-channel eddy current detection instrument (3) through a lead or wireless connection, and comprises the multi-channel eddy current detection instrument (3), a flexible bag (21) and a flexible PCB detection probe (22), wherein the flexible PCB detection probe (22) is arranged on the side of the flexible bag (21) close to the detected object, and an arrayed eddy current detection sensor (221) is arranged on the flexible PCB detection probe (22) to form an ultrathin film detection probe.

[0015] When the irregular surface is detected, the flexible bag (21) presses the flexible PCB detection probe (22) provided with the arrayed eddy current detection sensor (221) against the irregular detection surface, and several eddy current detection sensors in the corresponding eddy current detection sensor units (221a, 221b, 221c, …, 221n) are extracted as sensor units for actual detection.

[0016] Further, the flexible bag (21) is provided with ferroferrite powder (212) packaged in a flexible film layer (211). The ferroferrite powder (212) is flowable like sand in a sandbag, and is packaged in the flexible film layer to form a sandbag device, which can be deformed arbitrarily to make the flexible PCB eddy current detection probe on the outer side of the flexible bag conform to different curved surfaces, so as to selectively obtain actual detection data of several arrayed eddy current detection sensors on the probe as defect analysis and evaluation of the detected object.

[0017] Further, the flexible bag (21) is further provided with a spacing detection sensor device (213) for detecting the spacing between the sensor device (213) and each eddy current detection sensor on the flexible PCB. Through the detected spacing, the multi-channel eddy current detection instrument extracts the detection signal of the corresponding area eddy current detection sensor to realize targeted area detection, such as separate evaluation of the defect parameters of the concave surface. The spacing detection sensor device (213) for detecting the spacing with each eddy current detection sensor can be one of a planar coil or a capacitor plate, and the capacitance value between the spacing detection sensor device (213) and each eddy current detection sensor is detected to serve as a parameter for calculating the spacing value.

[0018] Further, the multi-channel eddy current detection instrument (3) selects the eddy current detection sensor with a spacing value greater than that when not fitted as a real-time detection sensor to extract the corresponding detection signal data for defect information analysis and evaluation.

[0019] Furthermore, the retrieval device (2) also includes a series of individual flexible bags (21) assembled together, each flexible bag (21) being equipped with a corresponding flexible PCB board eddy current detection probe (22) and a spacing detection sensor device (213). During real-time eddy current detection, each flexible bag (21) deforms a corresponding groove surface to form an individual detection probe.

[0020] Based on the above technical solution, the present invention has the following beneficial effects: The present invention adopts a flexible "sandbag" form, that is, ferrite powder is filled in a long, flexible bag and pressed onto an array eddy current sensor made of a flexible PCB board during use. This detection method significantly reduces the frequency of use of the flexible PCB array eddy current sensor, increases the effective penetration depth of the eddy current, and better ensures effective adhesion between the flexible sensor and the workpiece, thereby achieving the expected detection performance improvement. Furthermore, the array sensor composed of flexible PCB eddy current coils can also be bonded to the flexible "sandbag," making it more suitable for the actual detection of array-type eddy current detection devices on ultra-thin flexible circuit boards, thus facilitating engineering applications. Attached Figure Description

[0021] Figure 1 This is a schematic diagram showing the usage state of the monitoring device according to the preferred embodiment of the present invention.

[0022] Figure 2 This is a cross-sectional schematic diagram of the monitoring device in use for detecting the status of the device according to the preferred embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the array-type detection sensor structure in the flexible PCB board detection probe of the preferred embodiment of the present invention;

[0024] Figure 4 This is a schematic diagram of the detection device structure according to the preferred embodiment of the present invention;

[0025] Figure 5 This is a cross-sectional view of the detection device according to the preferred embodiment of the present invention;

[0026] Figure 6 This is a schematic diagram of the detection device structure according to the preferred embodiment of the present invention;

[0027] Figure 7 This is a cross-sectional schematic diagram of the detection device structure according to the preferred embodiment of the present invention;

[0028] Figure 8 This is a cross-sectional view of the detection device according to the preferred embodiment of the present invention;

[0029] Figure 9 This is a schematic diagram of the sensor spacing detection device according to the preferred embodiment of the present invention;

[0030] Figure 10 This is a schematic diagram of the sensor spacing detection device according to the preferred embodiment of the present invention;

[0031] Figure 11 This is a schematic diagram of the detection device structure according to the preferred embodiment of the present invention;

[0032] Figure 12 A cross-sectional view of the detection device according to the preferred embodiment of the present invention;

[0033] Figure 13 This is a schematic diagram of the array-type detection sensor structure in the flexible PCB board detection probe of the preferred embodiment of the present invention;

[0034] Figure 14 This is a schematic diagram of the array-type detection sensor structure in the flexible PCB board detection probe of the preferred embodiment of the present invention;

[0035] Figure 15 This is a schematic diagram of the array-type detection sensor structure in the flexible PCB board detection probe, which is the preferred embodiment of the present invention. Detailed Implementation

[0036] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0037] like Figures 1 to 10 As shown, a method for improving the eddy current testing performance of flexible PCB boards is used for eddy current testing of metal devices with irregularly curved detection surfaces, such as tenons 11 in rotor blade mounting devices for aircraft engines. The method involves pressing a flexible PCB board detection probe equipped with an array of eddy current sensors against the irregular detection surface using a deformable sandbag-like flexible bag, and then extracting the corresponding detection signal data. The specific steps are as follows:

[0038] a. Placement of the detection device: Prepare a flexible bag of appropriate size and width and a flexible PCB board detection probe combination. The flexible bag will hold the array of eddy current detection sensors set on the PCB board detection probe. The multi-channel array eddy current detector will operate each eddy current sensor to detect, and the eddy current detector will acquire the detection signal data of each eddy current detection sensor.

[0039] b. Selecting the detection sensor: When the flexible PCB board is deformed and attached to the irregular detection surface, select the eddy current detection sensor for the actual detection.

[0040] c. Actual testing: Apply an excitation power supply of a corresponding frequency to the array-type eddy current detection sensor on the flexible PCB board, perform eddy current non-destructive testing on the object under test, and extract the corresponding detection signal data;

[0041] d. Detection data analysis: Analyze the extracted detection signal data and evaluate the defect parameters of the detected object.

[0042] like Figure 2 and Figure 5 As shown, the interior of the deformable flexible bag is filled with ferrite powder 212. The sandbag-like flexible bag formed by the ferrite powder can not only effectively adhere the flexible PCB board probe to the curved surface being detected, but also, as a good magnetic conductor, ferrite enhances the detection performance and increases the effective penetration depth of the eddy current detection signal. Consequently, it can significantly reduce the detection frequency of the flexible PCB array eddy current sensor and improve the detection performance.

[0043] Step b involves selecting a detection sensor by measuring the distance between each sensor in the array of sensors on the flexible PCB board eddy current detection probe and the center of the flexible bag, and comparing the distance changes before and after bonding to select the actual sensor for detection.

[0044] like Figure 9 and Figure 10 As shown, by comparing the spacing values ​​between the sensor device mounted on the flexible bag and each sensor on the flexible PCB board before and after bonding detection, the changes in the spacing values ​​are evaluated and analyzed to select the appropriate sensor for actual eddy current detection in the array-type sensing. The sensor device mounted on the flexible bag is a capacitive detection sensor. A preferred implementation is to analyze and calculate the spacing between the sensor device and the eddy current detection sensor by measuring the capacitance change between the capacitive electrode or planar spiral coil and the eddy current sensor coil. The multi-channel eddy current detection instrument selects an eddy current detection sensor whose spacing value during bonding detection is greater than that before bonding, as the real-time detection sensor. In many cases, it is necessary to detect the concave and irregular surfaces of metal components, such as the mounting grooves of turbine blades in aero-engines. Defects in the grooved areas are more difficult to detect and it is more difficult to fit a suitable probe for detection. Figure 9 and Figure 10 As shown, the distance value between the eddy current detection sensor unit 221a and the distance detection sensor device 213 located at the center of the flexible bag away from the detection surface is A1 when not in contact and A2 when in contact. In the case of changes in the concave curvature of the detection surface, A2 is greater than A1, and is therefore selected as the sensor unit for actual detection. However, the eddy current detection sensor unit 221b has a distance value of B1 when not in contact and B2 when in contact. In the case of changes in the concave curvature of the detection surface, B2 is less than B1, and is not selected as the sensor unit for actual detection when it is necessary to detect the concave curvature of the detection surface.

[0045] like Figures 6 to 12As shown, this invention also discloses a flexible PCB board eddy current testing device for eddy current testing of metal devices with irregular arc-shaped curved surfaces, such as the tenon 11 in the rotor blade 1 mounting device of an aero-engine. The flexible PCB board eddy current testing device 2 is connected to a multi-channel eddy current testing instrument 3 via a lead wire or wireless connection. The testing device includes a multi-channel eddy current testing instrument 3, a flexible bag 21, and a flexible PCB board testing probe 22. The flexible PCB board testing probe 22 is disposed on the side of the flexible bag 21 near the object being tested. An array of eddy current sensors 221 is disposed on the flexible PCB board testing probe 22 to form an ultra-thin film-type testing probe. When testing an object with an irregular surface, the flexible bag 21 presses the flexible PCB board testing probe 22 with the array of eddy current sensors 221 tightly against the irregular testing surface, and extracts several eddy current sensors from the corresponding eddy current sensor units 221a, 221b, 221c, ..., 221n as the actual sensor units used for testing and evaluation.

[0046] like Figure 7 As shown, the flexible bag 21 is configured to contain ferrite powder 212 packaged within the flexible membrane layer 211. The ferrite powder 212, like sand in a sandbag, is flowable and, when packaged within the flexible membrane layer, forms a sandbag-like device that can deform arbitrarily. This causes the flexible PCB board eddy current detection probe on the outer side of the flexible bag to conform to different curved surfaces, thereby selectively acquiring the actual detection data from several array-type eddy current detection sensors on the probe, which is then used for defect analysis and evaluation of the object being inspected.

[0047] like Figure 8 As shown, a spacing detection sensor device 213 is also provided on the flexible bag 21 to detect the spacing between the sensor device 213 and each eddy current detection sensor on the flexible PCB board. Based on the detected spacing, the multi-channel eddy current testing instrument extracts the detection signals from the eddy current detection sensors in the corresponding area, enabling targeted area detection, such as individually evaluating defect parameters of the concave surface. The spacing detection sensor device 213, used to detect the spacing between each eddy current detection sensor, can be either a planar coil or a capacitor electrode. The capacitance value between the spacing detection sensor device 213 and each eddy current detection sensor is used as a parameter to calculate the spacing value. The multi-channel eddy current testing instrument 3 selects an eddy current detection sensor whose spacing value during bonding detection is greater than that during non-bonding detection as the real-time detection sensor, extracting the corresponding detection signal data for analysis and evaluation of defect information. The spacing detection sensor device 213 is positioned at the center of the flexible bag on the side furthest from the surface being tested via a mounting plate 214.

[0048] like Figure 11 and Figure 12As shown, the retrieval device 2 also includes a series of individual flexible bags 21 assembled together. Each flexible bag 21 is equipped with a corresponding flexible PCB board eddy current detection probe 22 and a spacing detection sensor device 213. During real-time eddy current detection, each flexible bag 21 deforms a corresponding groove surface to form an individual detection probe.

[0049] And, such as Figures 13 to 15 The array-type eddy current detection sensor on the flexible PCB board eddy current search probe shown is a typical planar spiral detection sensor, such as... Figure 13 The middle component is a circular planar spiral detection sensor. Figure 14 The center is a square planar spiral eddy current detection sensor coil. It can also be configured as follows: Figure 15 The array-type eddy current detection sensor, which consists of double-layer coils arranged in an alternating pattern, is more suitable for large-area coverage and flexible circuit board bonding to detection surfaces with different curvatures. When stretched and the angle is changed, it can completely cover the detection surface without missing any detections.

[0050] 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 method for improving the eddy current detection performance of flexible PCB boards, characterized in that... A technique for extracting corresponding detection signal data involves pressing a flexible PCB board detection probe equipped with an array of eddy current detection sensors against an irregular detection surface using a deformable, sandbag-like flexible bag. The interior of the deformable, flexible bag is filled with ferrite powder. The specific steps are as follows: a. Placement of the detection device: Prepare a flexible bag of appropriate size and width and a flexible PCB board detection probe combination. The flexible bag will hold the array of eddy current detection sensors set on the PCB board detection probe. The multi-channel array eddy current detector will operate each eddy current sensor to detect, and the eddy current detector will acquire the detection signal data of each eddy current detection sensor. b. Selecting the detection sensor: When the flexible PCB board is deformed and attached to the irregular detection surface, select the eddy current detection sensor for the actual detection. c. Actual testing: Apply an excitation power supply of the corresponding frequency to the array-type eddy current detection sensor on the flexible PCB board, perform eddy current non-destructive testing on the object under test, and extract the corresponding detection signal data; d. Detection data analysis: Analyze the extracted detection signal data and evaluate the defect parameters of the detected object.

2. The method for improving the eddy current detection performance of flexible PCB boards according to claim 1, characterized in that... In step b, the detection sensor is selected by measuring the distance between each sensor in the array of sensors on the flexible PCB board eddy current detection probe and the center of the flexible bag, and comparing the distance changes before and after bonding to select the actual sensor to be detected.

3. The method for improving the eddy current detection performance of flexible PCB boards according to claim 2, characterized in that... By comparing the spacing between the sensor device set on the flexible bag and each sensor on the flexible PCB board before and after bonding detection, the changes in the spacing values ​​are evaluated and analyzed to select the sensor for actual eddy current detection in the array-type sensing.

4. The method for improving the eddy current detection performance of flexible PCB boards according to claim 3, characterized in that... The multi-channel eddy current testing instrument selects an eddy current testing sensor whose spacing value during bonding testing is greater than that during non-bonding testing as the real-time testing sensor.

5. A flexible PCB board eddy current testing device, comprising a multi-channel eddy current testing instrument (3), a flexible bag (21), and a flexible PCB board testing probe (22), characterized in that... The flexible PCB board detection probe (22) is disposed on the side of the flexible bag (21) near the object being detected, and the array-type eddy current detection sensor (221) is disposed on the flexible PCB board detection probe (22); In the case of detecting an irregular surface, the flexible bag (21) presses the flexible PCB board detection probe (22) equipped with an array of eddy current detection sensors (221) against the irregular surface, and extracts several eddy current detection sensors from the corresponding eddy current detection sensor unit as the actual detection sensor unit used for detection and evaluation.

6. The eddy current detection device for flexible PCB boards according to claim 5, characterized in that... The flexible bag (21) is configured to contain ferrite powder (212) packaged inside a flexible film layer (211).

7. The eddy current detection device for flexible PCB boards according to claim 5, characterized in that... The flexible bag (21) is also provided with a spacing detection sensor device (213) for detecting the spacing between the sensor device (213) and each eddy current detection sensor on the flexible PCB board.

8. The eddy current detection device for flexible PCB boards according to claim 7, characterized in that... The multi-channel eddy current testing instrument (3) selects an eddy current testing sensor whose spacing value during bonding testing is greater than that during non-bonding testing as a real-time testing sensor, and extracts the corresponding testing signal data to analyze and evaluate defect information.

9. The eddy current detection device for flexible PCB boards according to claim 5, characterized in that... The detection device (2) also includes a number of individual flexible bags (21) spliced ​​together, each flexible bag (21) being equipped with a corresponding flexible PCB board detection probe (22) and a spacing detection sensor device (213).

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