A rolling eddy current detection positioning device, positioning method and detection device thereof

Abstract

This invention discloses a rolling eddy current testing positioning device, its positioning method, and a testing device, applicable to in-service testing of large-area rough metal surfaces. The positioning device of the rolling eddy current non-destructive testing device evaluates and determines the corresponding position status of the array-type eddy current sensors in the rolling eddy current testing probe by using the signal sensed by the metal positioning device on the eddy current testing sensor, thereby extracting or activating the corresponding detection signal or testing operation of the corresponding eddy current sensor.

Description

Technical Field

[0001] This invention relates to the field of nondestructive testing technology, specifically to a positioning method and testing device for rolling inspection of large-area metal surfaces, and particularly to a rolling eddy current testing positioning device and its positioning method and testing device. Background Technology

[0002] Eddy current testing technology is currently the best and fastest non-destructive testing method for in-service equipment with rough metal surfaces, such as those with welds. Because it does not require a coupling agent and can penetrate the anti-corrosion layer of welds and other surfaces, its application has become increasingly widespread with the advent of orthogonal omnidirectional eddy current sensors. However, since current orthogonal eddy current sensor arrays are mainly linear arrays, the contact with the weld or other surfaces during testing is sliding. This makes the eddy current sensor susceptible to scratches on uneven metal surfaces with sharp corners, affecting its service life.

[0003] To address the above-mentioned shortcomings, the present invention adopts the following technical solution. Summary of the Invention

[0004] The purpose of this invention is to provide a rolling eddy current detection and positioning device, its positioning method, and the detection device. The disclosed technical solution is as follows:

[0005] A rolling eddy current detection positioning device is applicable to in-service inspection of the metal surface of a large-area rough object (1). The positioning device of the rolling eddy current non-destructive testing device (2) uses the signal sensed by the metal positioning device on the eddy current sensor to evaluate and determine the corresponding position state of the arrayed eddy current sensors in the rolling eddy current detection probe, thereby extracting or activating the corresponding detection signal or detection operation of the eddy current sensor. The eddy current detection positioning device includes a cylindrical roller (21), an arrayed eddy current sensor (22), and a rolling device (23). The arrayed eddy current sensors (22) are arranged in several rows uniformly arranged axially, with each row of arrayed eddy current sensors (22) forming a uniform distribution.

[0006] It also includes a positioning pointer (24), which includes a metal gravity ball (241), a rocker arm (242), and a rotary joint (243). The metal gravity ball (241) is rotatably mounted on the rotary joint (243) through the end of the rocker arm (242), so that the metal gravity ball (241) is always kept at a point in the radial direction of the roller due to gravity.

[0007] Furthermore, during the detection process, the array-type eddy current detection sensor (22) extracts the signal value closest to the metal gravity ball (241) to determine which row of array-type eddy current detection sensors (22) is used as the sensor for current eddy current detection in the rolling detection device.

[0008] Furthermore, the positioning pointer (24) is located on one side of the cylindrical roller (21).

[0009] Furthermore, the rolling device (23) includes a rolling shaft (231) for the roller (21) to rotate, and the rolling shaft (231) is a whole rolling bearing arranged on the center line inside the roller (21).

[0010] Furthermore, the positioning pointer (24) is mounted on the rolling shaft (231), wherein the rotary joint (243) is disposed on the rolling shaft (231).

[0011] Furthermore, the metal gravity ball (241) of the positioning pointer (24) is rotatably connected to one end of the rolling shaft (231) via a rocker arm (242).

[0012] This invention also discloses a rolling eddy current detection and positioning method, using the positioning device described above, and the specific method steps are as follows:

[0013] a. Signal calibration process: During the scanning and detection, the metal gravity ball of the metal positioning device is always kept at a point in the radial direction of the roller; therefore, during the calibration process, the array-type eddy current detection sensor selects a fixed working frequency, and when a certain sensor rolls and rotates to the position of the metal gravity ball, the detected eddy current signal value is used as the standard calibration value.

[0014] b. Sensor selection process: Among the roller surface sensors, the row of arrayed eddy current detection sensors located on the axial straight line of the roller where a sensor that detected the calibration value is located is selected as the sensor for actual detection.

[0015] c. Actual detection process: In the rolling eddy current scanning detection, the array of eddy current detection sensors attached to the surface of the roller of the rolling detection device repeatedly performs the actual detection sensor positioning selection and extracts real-time detection signal values ​​as described in step b during the rolling process.

[0016] An alternating magnetic field is generated in the sensor coil. When a metal gravity sphere approaches the magnetic field, an induced current is generated on the surface of the sphere. Simultaneously, this eddy current field also generates an alternating magnetic field in the opposite direction to that of the coil. Due to this reaction, the amplitude and phase of the high-frequency current in the coil are altered (the effective impedance of the coil). This change is related to parameters such as the permeability and conductivity of the metal, the geometry and dimensions of the coil, the current frequency, and the distance between the coil and the metal gravity sphere. Typically, the metal gravity sphere is made of a uniform metal conductor with linear and isotropic properties; that is, the permeability and conductivity of the metal, and the geometry and dimensions of the coil are fixed parameters. With a fixed load applied to the coil, the characteristic impedance Z of the coil becomes a single-valued function of the distance D. In other words, the magnitude of the output signal varies with the distance between the coil and the surface of the metal gravity sphere. Because eddy current electromagnetic signals are very sensitive to distance and have a skin effect, there is no signal beyond a very small distance; generally, there is no signal beyond 10mm.

[0017] Furthermore, in step b, the sensor selection process is carried out by extracting the detection signals of a selected row of sensors as detection values.

[0018] Furthermore, in step b, the sensor selection process involves using a switch to select a row of sensors whose detection signals are used as the detection values. The switch can be activated by either a slip ring contact's on / off signal or an analog switch synchronization signal to select a row of array-type sensors as the actual detection sensors.

[0019] The present invention also discloses a rolling eddy current detection device, which uses the positioning device described above. The array-type eddy current detection sensors (22) are uniformly distributed on a cylindrical roller (21) through a protective film layer (25) to form multiple rows of uniformly axially arranged sensors, constituting a rolling eddy current detection probe (3), which is connected to an array eddy current meter (4). A handle (5) can also be provided for convenient detection. Thus, during the rolling scanning detection process, only one set of linear array eddy current coils is contacted each time, and the device is connected to the array eddy current meter for data analysis and processing. Furthermore, the on / off signal of a slip ring contact or analog switch is used as a synchronization signal to form a scanning detection imaging display.

[0020] Furthermore, the roller (21) is also configured as a soft and deformable intermediate spacer layer (211), so that when the object being tested (1) is uneven, all the array of detection sensors actually detected by the rolling eddy current probe (3) can be completely attached to the detection surface. The soft and deformable intermediate spacer layer (211) can be made of semi-soft materials such as sponge, rubber or silicone.

[0021] Based on the above technical solution, the present invention has the following beneficial effects: The present invention employs a rolling cylindrical surface uniformly distributed array eddy current sensor design. During detection, a slip ring contact or analog switch is used for switching, ensuring that only one set of axially arranged linear array eddy current sensors on the cylindrical surface is contacted at a time, and linked with the array eddy current meter. Simultaneously, the on / off signal of the slip ring contact or analog switch is used as a synchronization signal to form a scanning image. This greatly reduces wear on the eddy current sensors when used on rough detection surfaces. Furthermore, by using the actual sensors detected in the array eddy current detection probe as positioning signals, the conventional encoder disk accessory is omitted. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the detection device structure according to the preferred embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the detection device structure according to the preferred embodiment of the present invention;

[0024] Figure 3 This is a cross-sectional schematic diagram of the detection device structure according to the preferred embodiment of the present invention;

[0025] Figure 4 This is a schematic diagram of the detection device structure according to the preferred embodiment of the present invention;

[0026] Figure 5 This is a schematic diagram of the detection device structure according to the preferred embodiment of the present invention;

[0027] Figure 6 This is a schematic diagram of the detection device in use according to the preferred embodiment of the present invention;

[0028] Figure 7 This is a schematic diagram illustrating the positioning principle of the preferred embodiment of the present invention. Detailed Implementation

[0029] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0030] like Figures 1 to 5 As shown, a rolling eddy current testing positioning device is suitable for in-service testing of the metal surface of a large-area, rough object 1. The positioning device of the rolling eddy current non-destructive testing device 2 uses the signal sensed by the metal positioning device on the eddy current sensor to evaluate and determine the corresponding position state of the arrayed eddy current sensors in the rolling eddy current testing probe, thereby extracting or activating the corresponding detection signal or testing operation of the eddy current sensor. The eddy current testing positioning device includes a cylindrical roller 21, an arrayed eddy current sensor 22, and a rolling device 23. The arrayed eddy current sensors 22 are arranged in several rows uniformly arranged axially, with each row of arrayed eddy current sensors 22 forming a uniform distribution.

[0031] like Figure 1 The diagram also includes a positioning pointer 24, which comprises a metal gravity ball 241, a swing arm 242, and a rotary joint 243. The metal gravity ball 241 is rotatably mounted on the rotary joint 243 via the end of the swing arm 242, causing the metal gravity ball 241 to remain at a single point in the radial direction of the roller due to gravity. Furthermore, during the detection process, the array-type eddy current detection sensors 22 extract the signal value closest to the metal gravity ball 241 to determine which row of array-type eddy current detection sensors 22 is used as the sensor for current eddy current detection in the rolling detection device. The positioning pointer 24 is located on one end side of the cylindrical roller 21.

[0032] like Figure 2 and Figure 6 As shown, the rolling device 23 includes a rolling shaft 231 for rotating the roller 21. The rolling shaft 231 is a single rolling bearing located on the center line inside the roller 21. The positioning pointer 24 is mounted on the rolling shaft 231, and the rotary joint 243 is located on the rolling shaft 231.

[0033] like Figures 1 to 3 As shown, the metal gravity ball 241 of the positioning pointer 24 is rotatably connected to one end of the rolling shaft 231 via the rocker arm 242.

[0034] This invention also discloses a rolling eddy current detection and positioning method, using the positioning device described above, with the specific method steps as follows:

[0035] a. Signal calibration process: During the scanning and detection, the metal gravity ball of the metal positioning device is always kept at a point in the radial direction of the roller; therefore, during the calibration process, the array-type eddy current detection sensor selects a fixed working frequency, and when a certain sensor rolls and rotates to the position of the metal gravity ball, the detected eddy current signal value is used as the standard calibration value.

[0036] b. Sensor selection process: Among the roller surface sensors, the row of arrayed eddy current detection sensors located on the axial straight line of the roller where a sensor that detected the calibration value is located is selected as the sensor for actual detection.

[0037] c. Actual detection process: In the rolling eddy current scanning detection, the array of eddy current detection sensors attached to the surface of the roller of the rolling detection device repeatedly performs the actual detection sensor positioning selection and extracts real-time detection signal values ​​as described in step b during the rolling process.

[0038] In step b, the sensor selection process can be implemented by extracting the detection signals of a selected row of sensors individually as the detection values. Alternatively, in step b, the sensor selection process can be implemented by switching the detection signals of a selected row of sensors as the detection values ​​using a switch. The switching method can be either an on / off signal from a slip ring contact or an analog switch synchronization signal to select a row of array-type detection sensors as the actual sensors to be detected.

[0039] like Figure 7 As shown, an alternating magnetic field is generated in the sensor coil. When the metal gravity sphere approaches the magnetic field, an induced current is generated on the surface of the metal gravity sphere. Simultaneously, this eddy current field also generates an alternating magnetic field in the opposite direction to the coil. Due to its reaction, the amplitude and phase of the high-frequency current in the coil are changed (the effective impedance of the coil). This change is related to parameters such as the permeability and conductivity of the metal body, the geometry and dimensions of the coil, the current frequency, and the distance between the coil and the metal gravity sphere. Typically, the metal gravity sphere is made of a uniform metal conductor with linear and isotropic properties, meaning that the permeability and conductivity of the metal body, and the geometry and dimensions of the coil are fixed parameters. With a fixed load applied to the coil, the electrical characteristic U value of the coil becomes a single-valued function of the distance D, meaning the magnitude of the output signal varies with the distance between the coil and the surface of the metal gravity sphere. Because eddy current electromagnetic signals are very sensitive to distance and have a skin effect, there is no signal beyond a very small distance; generally, there is no signal beyond 10 mm.

[0040] like Figure 6 As shown, the present invention also discloses a rolling eddy current detection device. Using the above positioning device, array-type eddy current detection sensors 22 are uniformly distributed on a cylindrical roller 21 through a protective film layer 25 to form multiple rows with uniform axial direction, forming a rolling eddy current detection probe 3, which is connected to an array eddy current meter 4. A handle 5 can also be provided for convenient detection. Thus, during the rolling scanning detection process, only one set of linear array eddy current coils is contacted at a time, and the device is connected to the array eddy current meter for data analysis and processing. Furthermore, the on / off signal of a slip ring contact or analog switch is used as a synchronization signal to form a scanning detection imaging display.

[0041] like Figure 4 and Figure 5 As shown, the roller 21 is also configured as a soft and deformable intermediate spacer layer 211, so that when the object being tested 1 is uneven, all the array of detection sensors actually detected by the rolling eddy current probe 3 can completely adhere to the detection surface. The soft and deformable intermediate spacer layer 211 can be made of semi-soft materials such as sponge, rubber, or silicone.

[0042] 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 rolling eddy current inspection positioning device comprising a cylindrical drum (21), an array eddy current inspection sensor (22), and a rolling means (23), characterised in that The array eddy current detection sensor (22) forms several rows of array eddy current detection sensors arranged in axial uniformity, and each row of array eddy current detection sensors forms a uniform distribution; The positioning pointer (24) is arranged on one end side of the cylindrical roller (21), and the positioning pointer (24) comprises a metal gravity ball (241), a swing rod (242) and a rotary joint (243). The metal gravity ball (241) is rotatably mounted on the rotary joint (243) through the end of the swing rod (242), so that the metal gravity ball (241) always remains at one point in the radial direction of the roller due to gravity. In the detection process, the signal value closest to the metal gravity ball (241) is extracted, and one row of array eddy current detection sensors (22) is determined as the sensor used in the current eddy current detection in the rolling detection device.

2. A rolling eddy current detection positioning device according to claim 1, wherein The rolling device (23) comprises a rolling shaft (231) for the rotation of the roller (21), and the rolling shaft (231) is a complete rolling bearing arranged on the center line in the roller (21).

3. A rolling eddy current detection positioning device according to claim 2, wherein The positioning pointer (24) is mounted on the rolling shaft (231), and the rotary joint (243) is arranged on the rolling shaft (231).

4. A rolling eddy current detection positioning device according to claim 3, wherein The metal gravity ball (241) of the positioning pointer (24) is freely rotatably connected to one end of the rolling shaft (231) through the swing rod (242).

5. A rolling eddy current detection positioning method characterized by The positioning device according to any one of the preceding claims is used, and the specific method steps are as follows: a. Signal calibration process: in the scanning detection, the metal gravity ball of the metal positioning device always remains at one point in the radial direction of the roller; therefore, in the calibration process, under the fixed working frequency of the array eddy current detection sensor, when a certain sensor rolls and rotates to the position of the metal gravity ball, the detected eddy current signal value is taken as the standard calibration value; b. Sensor selection process: in the surface sensor of the roller, the array eddy current detection sensor in the axial straight line of the roller where the certain sensor detecting the calibration value is selected as the sensor for actual implementation of detection; c. Actual detection process: in the rolling eddy current scanning detection, the array eddy current detection sensor attached to the surface of the roller of the rolling detection device repeatedly selects the actual implementation of the detection sensor in the b step in the rolling process, and extracts the real-time detection signal value.

6. A rolling eddy current detection positioning method according to claim 5, characterised in that In the sensor selection process in the b step, the detection signal of the selected row of sensors is extracted as the detection value as the selection method.

7. A method of eddy current inspection according to claim 5, wherein In the sensor selection process in the b step, the detection signal of the selected row of sensors is switched as the detection value as the selection method.

8. A rolling eddy current inspection device characterized by The positioning device of any one of claims 1-4, wherein the arrayed eddy current detection sensor (22) is uniformly distributed on the cylindrical roller (21) by a protective film layer (25) to form multiple rows of axial uniformity, and the roller (21) is connected to the arrayed eddy current instrument (4) to form a rolling eddy current detection probe (3).

9. A rolling eddy current inspection device according to claim 8, wherein The roller (21) is further provided with a soft deformable intermediate layer (211), so that when the detected object (1) is uneven, the actual detection of the rolling eddy current detection probe (3) is completely attached to the detection surface.

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